APA (7th ed.) Citation

Etling, F. R. (1978). Intermediate string techniques. Forest R. Etling.

Chicago Style (17th ed.) Citation

Etling, Forest R. Intermediate String Techniques. Elgin: Forest R. Etling, 1978.

MLA (9th ed.) Citation

Etling, Forest R. Intermediate String Techniques. Forest R. Etling, 1978.