MLA

Lieb, Hans-Heinrich. Linguistic Variables : Towards a Unified Theory of Linguistic Variation. Amsterdam: Benjamins, 1993.

APA

Lieb, H. (1993). Linguistic variables : towards a unified theory of linguistic variation. Amsterdam: Benjamins.

Chicago

Lieb, Hans-Heinrich, Linguistic Variables: Towards a Unified Theory of Linguistic Variation. Amsterdam: Benjamins, 1993.