APA (7th ed.) Citation

Nilsson, U., & Spee, G. (2015). Detective Gordon: The first case (First American edition.). Gecko Press USA.

Chicago Style (17th ed.) Citation

Nilsson, Ulf, and Gitte Spee. Detective Gordon: The First Case. First American edition. [United States?]: Gecko Press USA, 2015.

MLA (8th ed.) Citation

Nilsson, Ulf, and Gitte Spee. Detective Gordon: The First Case. First American edition. Gecko Press USA, 2015.

Warning: These citations may not always be 100% accurate.