APA (7th ed.) Citation

(1927). In Palo Alto, California, USA. Original in possession of Heiner Becker.

Chicago Style (17th ed.) Citation

In Palo Alto, California, USA. Original in Possession of Heiner Becker. 1927.

MLA (8th ed.) Citation

In Palo Alto, California, USA. Original in Possession of Heiner Becker. 1927.

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