WILLISON, G. F. (1968). The pilgrim's progress notes. Cliff notes.
Lua i Stíl Chicago (17ú heag.)WILLISON, George F. The Pilgrim's Progress Notes. Nebraska: Cliff notes, 1968.
Lua MLA (9ú heag.)WILLISON, George F. The Pilgrim's Progress Notes. Cliff notes, 1968.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.