APA (7th ed.) Citation

Heisenberg, W. (1966). Introduction to the unified field theory. Interscience.

Chicago Style (17th ed.) Citation

Heisenberg, W. Introduction to the Unified Field Theory. London: Interscience, 1966.

MLA (9th ed.) Citation

Heisenberg, W. Introduction to the Unified Field Theory. Interscience, 1966.