Cita APA (7a ed.)

Sommers, F. T., & Englebretsen, G. (2000). An invitation to formal reasoning: The logic of terms. Ashgate.

Cita Chicago Style (17a ed.)

Sommers, Frederic Tamler, y George Englebretsen. An Invitation to Formal Reasoning: The Logic of Terms. Aldershot, Hants, England ; Burlington, Vt.: Ashgate, 2000.

Cita MLA (9a ed.)

Sommers, Frederic Tamler, y George Englebretsen. An Invitation to Formal Reasoning: The Logic of Terms. Ashgate, 2000.