APA (7th ed.) Citation

Berthold, V. M. (2012). The Die Varieties of the Nesbitt Series of United States Envelopes. Project Gutenberg.

Chicago Style (17th ed.) Citation

Berthold, Victor M. The Die Varieties of the Nesbitt Series of United States Envelopes. Project Gutenberg, 2012.

MLA (9th ed.) Citation

Berthold, Victor M. The Die Varieties of the Nesbitt Series of United States Envelopes. Project Gutenberg, 2012.

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