APA (7th ed.) Citation

Mohrmann, C., Norman, F., & Sommerfelt, A. (1963). Trends in modern linguistics. Spectrum.

Chicago Style (17th ed.) Citation

Mohrmann, Christine, Frederick Norman, and Alf Sommerfelt. Trends in Modern Linguistics. Utrecht: Spectrum, 1963.

MLA (9th ed.) Citation

Mohrmann, Christine, et al. Trends in Modern Linguistics. Spectrum, 1963.