APA (7th ed.) Citation

Witkop, B. Paul Ehrlich and his magic bullets - revisited. Proceedings of the America Philosophical Society, 540-557.

Chicago Style (17th ed.) Citation

Witkop, Bernhard. "Paul Ehrlich and His Magic Bullets - Revisited." Proceedings of the America Philosophical Society : 540-557.

MLA (8th ed.) Citation

Witkop, Bernhard. "Paul Ehrlich and His Magic Bullets - Revisited." Proceedings of the America Philosophical Society, , pp. 540-557.

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