Burd, H. (1999). The history of PLAXIS.
Lua i Stíl Chicago (17ú heag.)Burd, H. The History of PLAXIS. 1999.
Lua MLA (9ú heag.)Burd, H. The History of PLAXIS. 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)