APA (7th ed.) Citation

Shiel, M. P., & Hartwell, D. G. (1977). The purple cloud. Gregg Press.

Chicago Style (17th ed.) Citation

Shiel, M. P., and David G. Hartwell. The Purple Cloud. Boston: Gregg Press, 1977.

MLA (9th ed.) Citation

Shiel, M. P., and David G. Hartwell. The Purple Cloud. Gregg Press, 1977.

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