diff --git a/api/src/main/java/de/epiceric/shopchest/api/ShopManager.java b/api/src/main/java/de/epiceric/shopchest/api/ShopManager.java
index 56272c6..b1492f3 100644
--- a/api/src/main/java/de/epiceric/shopchest/api/ShopManager.java
+++ b/api/src/main/java/de/epiceric/shopchest/api/ShopManager.java
@@ -3,7 +3,6 @@ package de.epiceric.shopchest.api;
 import java.util.Collection;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
-import java.util.function.Consumer;
 
 import org.bukkit.Location;
 import org.bukkit.OfflinePlayer;
@@ -80,7 +79,7 @@ public interface ShopManager {
      * @param sellPrice     the price a player can sell the product for.
      * @return a completable future returning the new shop
      * @since 1.13
-     * @see ShopManager#addAdminShop(ShopProduct, Location, double, double, Consumer, Consumer)
+     * @see ShopManager#addAdminShop(ShopProduct, Location, double, double)
      */
     CompletableFuture<Shop> addShop(OfflinePlayer vendor, ShopProduct product, Location location, double buyPrice, double sellPrice);
 
@@ -98,7 +97,7 @@ public interface ShopManager {
      * @param sellPrice     the price a player can sell the product for.
      * @return a completable future returning the new shop
      * @since 1.13
-     * @see ShopManager#addShop(OfflinePlayer, ShopProduct, Location, double, double, Consumer, Consumer)
+     * @see ShopManager#addShop(OfflinePlayer, ShopProduct, Location, double, double)
      */
     CompletableFuture<Shop> addAdminShop(ShopProduct product, Location location, double buyPrice, double sellPrice);
 
diff --git a/api/src/main/java/de/epiceric/shopchest/api/event/ShopSelectItemEvent.java b/api/src/main/java/de/epiceric/shopchest/api/event/ShopSelectItemEvent.java
index c7e379e..85040b5 100644
--- a/api/src/main/java/de/epiceric/shopchest/api/event/ShopSelectItemEvent.java
+++ b/api/src/main/java/de/epiceric/shopchest/api/event/ShopSelectItemEvent.java
@@ -140,7 +140,7 @@ public class ShopSelectItemEvent extends Event implements Cancellable {
      * Gets either the shop type of the shop being created, or whether the shop
      * is being edited
      * 
-     * @return the shop type or {@link Type#EDIT}
+     * @return the shop type or {@link SelectFlag.Type#EDIT}
      */
     public SelectFlag.Type getType() {
         return type;
diff --git a/api/src/main/java/de/epiceric/shopchest/api/shop/Shop.java b/api/src/main/java/de/epiceric/shopchest/api/shop/Shop.java
index 87650c0..6db28d7 100644
--- a/api/src/main/java/de/epiceric/shopchest/api/shop/Shop.java
+++ b/api/src/main/java/de/epiceric/shopchest/api/shop/Shop.java
@@ -1,7 +1,6 @@
 package de.epiceric.shopchest.api.shop;
 
 import java.util.Optional;
-import java.util.function.Consumer;
 
 import org.bukkit.Location;
 import org.bukkit.OfflinePlayer;
@@ -15,8 +14,8 @@ import de.epiceric.shopchest.api.exceptions.ChestNotFoundException;
  * Represents a shop
  * 
  * @since 1.13
- * @see ShopManager#addShop(OfflinePlayer, ShopProduct, Location, double, double, Consumer, Consumer)
- * @see ShopManager#addAdminShop(ShopProduct, Location, double, double, Consumer, Consumer)
+ * @see ShopManager#addShop(OfflinePlayer, ShopProduct, Location, double, double)
+ * @see ShopManager#addAdminShop(ShopProduct, Location, double, double)
  */
 public interface Shop {
 
diff --git a/core/src/main/java/de/epiceric/shopchest/database/Database.java b/core/src/main/java/de/epiceric/shopchest/database/Database.java
index 2d08450..fce03d5 100644
--- a/core/src/main/java/de/epiceric/shopchest/database/Database.java
+++ b/core/src/main/java/de/epiceric/shopchest/database/Database.java
@@ -799,6 +799,8 @@ public abstract class Database {
 
     /**
      * Gets whether the database has been fully initialized
+     * 
+     * @return whether the database is initialized
      */
     public boolean isInitialized() {
         return initialized;
diff --git a/core/src/main/java/de/epiceric/shopchest/shop/ShopImpl.java b/core/src/main/java/de/epiceric/shopchest/shop/ShopImpl.java
index b06a0cf..6ec7a78 100644
--- a/core/src/main/java/de/epiceric/shopchest/shop/ShopImpl.java
+++ b/core/src/main/java/de/epiceric/shopchest/shop/ShopImpl.java
@@ -145,7 +145,7 @@ public class ShopImpl implements Shop {
      * To update the shop in the database, it is necessary to update the shop in the database.
      * 
      * @param product the product
-     * @see Database#updateShop(Shop, Runnable, java.util.function.Consumer)
+     * @see Database#updateShop(Shop)
      */
     public void setProduct(ShopProduct product) {
         this.product = product;
@@ -189,7 +189,7 @@ public class ShopImpl implements Shop {
      * 
      * @param buyPrice the buy price
      * @throws IllegalStateException when a player can neither buy nor sell from this shop
-     * @see Database#updateShop(Shop, Runnable, java.util.function.Consumer)
+     * @see Database#updateShop(Shop)
      * @since 1.13
      */
     public void setBuyPrice(double buyPrice) {
@@ -213,7 +213,7 @@ public class ShopImpl implements Shop {
      * 
      * @param sellPrice the sell price
      * @throws IllegalStateException when a player can neither buy nor sell from this shop
-     * @see Database#updateShop(Shop, Runnable, java.util.function.Consumer)
+     * @see Database#updateShop(Shop)
      * @since 1.13
      */
     public void setSellPrice(double sellPrice) {
diff --git a/core/src/main/java/de/epiceric/shopchest/util/Counter.java b/core/src/main/java/de/epiceric/shopchest/util/Counter.java
index e0aacd8..ef73f3b 100644
--- a/core/src/main/java/de/epiceric/shopchest/util/Counter.java
+++ b/core/src/main/java/de/epiceric/shopchest/util/Counter.java
@@ -23,6 +23,8 @@ public final class Counter {
 
     /**
      * Increments the counter by one and returns itself
+     * 
+     * @return this counter
      */
     public final Counter increment() {
         this.value++;
@@ -31,6 +33,8 @@ public final class Counter {
 
     /**
      * Decrements the counter by one if its value is greater than zero and returns itself
+     * 
+     * @return this counter
      */
     public final Counter decrement() {
         this.value = Math.max(0, this.value - 1);
@@ -39,7 +43,9 @@ public final class Counter {
 
     /**
      * Sets the counter's value to the given value or zero if the given value is negative
+     * 
      * @param value the value to set the counter to
+     * @return this counter
      */
     public final Counter set(int value) {
         this.value = Math.max(0, value);
@@ -48,6 +54,8 @@ public final class Counter {
 
     /**
      * Returns the current value
+     * 
+     * @return the current value
      */
     public final int get() {
         return value;
diff --git a/core/src/main/java/de/epiceric/shopchest/util/NmsUtil.java b/core/src/main/java/de/epiceric/shopchest/util/NmsUtil.java
index b0dac16..69ce2ca 100644
--- a/core/src/main/java/de/epiceric/shopchest/util/NmsUtil.java
+++ b/core/src/main/java/de/epiceric/shopchest/util/NmsUtil.java
@@ -38,6 +38,8 @@ public class NmsUtil {
      * Gets the major version of the server
      * <p>
      * (e.g. 9 for v1_9_R2, 10 for v1_10_R1)
+     * 
+     * @return the major version
      */
     public static int getMajorVersion() {
         return Integer.parseInt(getServerVersion().split("_")[1]);