Haywood, R. (1987). All about P R. Mc Graw Hill.
Lua i Stíl Chicago (17ú heag.)Haywood, Roger. All About P R. London: Mc Graw Hill, 1987.
Lua MLA (9ú heag.)Haywood, Roger. All About P R. Mc Graw Hill, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.