APA (7th ed.) Citation

Roy, R. L. (1979). Underground houses: How to build a low-cost home. Sterling.

Chicago Style (17th ed.) Citation

Roy, Robert L. Underground Houses: How to Build a Low-cost Home. New York: Sterling, 1979.

MLA (9th ed.) Citation

Roy, Robert L. Underground Houses: How to Build a Low-cost Home. Sterling, 1979.

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