APA (7th ed.) Citation

Schuller, R. H. Tough times never last but tough people do [. Nightingale-Conant.

Chicago Style (17th ed.) Citation

Schuller, Robert H. Tough Times Never Last but Tough People Do [. Illinois: Nightingale-Conant.

MLA (9th ed.) Citation

Schuller, Robert H. Tough Times Never Last but Tough People Do [. Nightingale-Conant.

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