Owler, L. (1970). Wheldon's Costing Simplied Lwj. Owler. MacDonald & Evnas.
Lua i Stíl Chicago (17ú heag.)Owler, LWJ. Wheldon's Costing Simplied Lwj. Owler. MacDonald & Evnas, 1970.
Lua MLA (8ú heag.)Owler, LWJ. Wheldon's Costing Simplied Lwj. Owler. MacDonald & Evnas, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.