APA (7th ed.) Citation

Erdos, R. F. (1967). Teaching by correspondence / by R.F. Erdos. Longmans.

Chicago Style (17th ed.) Citation

Erdos, R. F. Teaching by Correspondence / by R.F. Erdos. Longmans, 1967.

MLA (9th ed.) Citation

Erdos, R. F. Teaching by Correspondence / by R.F. Erdos. Longmans, 1967.

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