Etling, F. R. (1978). Intermediate string techniques. Forest R. Etling.
Cita Chicago (17th ed.)Etling, Forest R. Intermediate String Techniques. Elgin: Forest R. Etling, 1978.
Cita MLA (9th ed.)Etling, Forest R. Intermediate String Techniques. Forest R. Etling, 1978.
Atenció: Aquestes cites poden no estar 100% correctes.