APA (7th ed.) Citation

Essler, W. K. (1971). Wissenschaftstheorie. Karl Alber.

Chicago Style (17th ed.) Citation

Essler, Wilhelm Karl. Wissenschaftstheorie. Freiburg [etc.]: Karl Alber, 1971.

MLA (9th ed.) Citation

Essler, Wilhelm Karl. Wissenschaftstheorie. Karl Alber, 1971.

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