APA (7th ed.) Citation

Bergstra, J. A., Heering, J., & Klint, P. (1987). ASF, an Algebraic Specification Formalism.

Chicago Style (17th ed.) Citation

Bergstra, Jan A., Jan Heering, and Paul Klint. ASF, an Algebraic Specification Formalism. Amsterdam, 1987.

MLA (9th ed.) Citation

Bergstra, Jan A., et al. ASF, an Algebraic Specification Formalism. 1987.