* MySQL-dokumentation - https://dev.mysql.com/doc/refman/8.0/en/string-functions.html#function_concat

* Stack Overflow - https://stackoverflow.com/questions/tagged/mysql-concat

* Tutorials Point - https://www.tutorialspoint.com/mysql/mysql-concat-function.htm

* W3Schools - https://www.w3schools.com/sql/func_mysql_concat.asp

* GeeksforGeeks - https://www.geeksforgeeks.org/mysql-concat-function/