APA (7th ed.) Citation

Duff, D. V. On the world's roof. Peal Press.

Chicago Style (17th ed.) Citation

Duff, Douglas V. On the World's Roof. [s.l.]: Peal Press.

MLA (9th ed.) Citation

Duff, Douglas V. On the World's Roof. Peal Press.

Warning: These citations may not always be 100% accurate.