Roberts, R. (2012). Yammer starter. Packt Publishing.
Lua i Stíl Chicago (17ú heag.)Roberts, Ralph. Yammer Starter. Birmingham, [Eng.]: Packt Publishing, 2012.
Lua MLA (9ú heag.)Roberts, Ralph. Yammer Starter. Packt Publishing, 2012.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.