APA

Langer S. K. K., . (1953). An introduction to symbolic logic. New York: Dover Publications.

Chicago

Langer Susanne Katherina Knauth, . 1953. An introduction to symbolic logic. New York: Dover Publications.

Harvard

Langer S. K. K., . (1953). An introduction to symbolic logic. New York: Dover Publications.

MLA

Langer Susanne Katherina Knauth, . An introduction to symbolic logic. New York: Dover Publications. 1953.