Lumsden, R. (1993). Twenty-three steps to success and achievement. Indus.
Lua i Stíl Chicago (17ú heag.)Lumsden, Robert. Twenty-three Steps to Success and Achievement. New delhi: Indus, 1993.
Lua MLA (9ú heag.)Lumsden, Robert. Twenty-three Steps to Success and Achievement. Indus, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.