Black, S. (1978). Practical public relations (4th.). Pitman.
Lua i Stíl Chicago (17ú heag.)Black, Sam. Practical Public Relations. 4th. London: Pitman, 1978.
Lua MLA (9ú heag.)Black, Sam. Practical Public Relations. 4th. Pitman, 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.