APA (7th ed.) Citation

Herbert, F., & Ferlinghetti, L. Thinking about the unthinkable.

Chicago Style (17th ed.) Citation

Herbert, Frank, and Lawrence Ferlinghetti. Thinking About the Unthinkable.

MLA (9th ed.) Citation

Herbert, Frank, and Lawrence Ferlinghetti. Thinking About the Unthinkable.

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