diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 79057d2..421ab10 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -3,16 +3,13 @@
 find_package(Boost 1.62 REQUIRED)
 find_package(SQLite3 REQUIRED)
 
-#set(CORE_HEADERS
-#    entity.h
-#    database.h
-#)
-
+set(CORE_HEADERS
+    entity.h
+    database.h
+)
 set(CORE_SOURCES
-    database.cpp
     entity.cpp
-    seller.cpp
-    article.cpp
+    database.cpp
 )
 
 add_library(core STATIC ${CORE_SOURCES})
diff --git a/src/core/article.cpp b/src/core/article.cpp
deleted file mode 100644
index 4ba0b33..0000000
--- a/src/core/article.cpp
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "article.h"
-
-Article::Article() : Entity()
-{}
-
-Article::Article(const std::shared_ptr<Seller> sellerPtr) : Entity()
-{
-    this->sellerPtr = sellerPtr;
-}
-
-void Article::setArticleNo(int articleNo)
-{
-    this->articleNo = articleNo;
-}
-
-void Article::setPrice(int price)
-{
-    this->price = price;
-}
-
-void Article::setDescription(const std::string& description)
-{
-    this->description = description;
-}
\ No newline at end of file
diff --git a/src/core/article.h b/src/core/article.h
deleted file mode 100644
index cc25ffa..0000000
--- a/src/core/article.h
+++ /dev/null
@@ -1,27 +0,0 @@
-#ifndef ARTICLE_H
-#define ARTICLE_H
-
-#include "entity.h"
-#include "seller.h"
-
-#include <string>
-#include <memory>
-
-class Seller;
-
-class Article : public Entity
-{
-public:
-    Article();
-    Article(std::shared_ptr<Seller> sellerPtr);
-    void setArticleNo(int articleNo);
-    void setPrice(int price);
-    void setDescription(const std::string& description);
-private:
-    std::shared_ptr<Seller> sellerPtr{};
-    int articleNo{};
-    int price{};
-    std::string description{};
-};
-
-#endif
\ No newline at end of file
diff --git a/src/core/entity.cpp b/src/core/entity.cpp
index 1368155..ac48025 100644
--- a/src/core/entity.cpp
+++ b/src/core/entity.cpp
@@ -13,8 +13,8 @@ void Entity::createUuid()
     uuid = generator();
 }
 
-void Entity::createUuidFromString(const std::string& uuidString)
+void Entity::createUuidFromString(const std::string& uuid_string)
 {
     boost::uuids::string_generator generator{};
-    uuid = generator(uuidString);
+    uuid = generator(uuid_string);
 }
\ No newline at end of file
diff --git a/src/core/entity.h b/src/core/entity.h
index 63f6229..b36d9a3 100644
--- a/src/core/entity.h
+++ b/src/core/entity.h
@@ -10,9 +10,9 @@ class Entity
   public:
     Entity();
     virtual ~Entity() = 0;
-    const boost::uuids::uuid& getUuid() const { return uuid; };
+    const boost::uuids::uuid& getUuid() { return uuid; };
     void createUuid();
-    void createUuidFromString(const std::string& uuidString);
+    void createUuidFromString(const std::string& uuid_string);
 
   private:
     boost::uuids::uuid uuid{};
diff --git a/src/core/seller.cpp b/src/core/seller.cpp
deleted file mode 100644
index 58861bd..0000000
--- a/src/core/seller.cpp
+++ /dev/null
@@ -1,26 +0,0 @@
-#include "seller.h"
-
-void Seller::setSellerNo(int seller_no)
-{
-    this->sellerNo = seller_no;
-}
-
-void Seller::setFirstName(const std::string& firstName)
-{
-    this->firstName = firstName;
-}
-
-void Seller::setLastName(const std::string& lastName)
-{
-    this->lastName = lastName;
-}
-
-void Seller::setNumberOfOfferedArticles(int number)
-{
-    numberOfOfferedArticles = number;
-}
-
-size_t Seller::getNumberOfOfferedArticles()
-{
-    return articles.size();
-}
\ No newline at end of file
diff --git a/src/core/seller.h b/src/core/seller.h
deleted file mode 100644
index 16edd98..0000000
--- a/src/core/seller.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#ifndef SELLER_H
-#define SELLER_H
-
-#include "entity.h"
-#include "article.h"
-
-#include <string>
-#include <vector>
-
-class Article;
-
-class Seller : public Entity
-{
-  public:
-    void setSellerNo(int sellerNo);
-    void setFirstName(const std::string& firstName);
-    void setLastName(const std::string& lastName);
-    void setNumberOfOfferedArticles(int number);
-
-    size_t getNumberOfOfferedArticles();
-
-  private:
-    int sellerNo{};
-    int numberOfOfferedArticles{};
-    std::string firstName{};
-    std::string lastName{};
-    std::vector<Article> articles{};
-};
-
-#endif
\ No newline at end of file