APA (7th ed.) Citation

Purtill, R. L. (1994). Logical thinking. Univ. Press of America.

Chicago Style (17th ed.) Citation

Purtill, Richard Lawrence. Logical Thinking. Lanham [u.a.]: Univ. Press of America, 1994.

MLA (9th ed.) Citation

Purtill, Richard Lawrence. Logical Thinking. Univ. Press of America, 1994.

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