APA (7th ed.) Citation

Carlson, L., & Richardson, L. (2012). Ruby: Receptury. Helion.

Chicago Style (17th ed.) Citation

Carlson, Lucas, and Leonard Richardson. Ruby: Receptury. [Gliwice, Poland?]: Helion, 2012.

MLA (8th ed.) Citation

Carlson, Lucas, and Leonard Richardson. Ruby: Receptury. Helion, 2012.

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