MLA

Akmajian, Adrian, and Frank Heny. Natural Language and Linguistic Theory. s.l.: s.n., n.d.

APA

Akmajian, A., & Heny, F. (n.d). Natural Language and Linguistic Theory. s.l.: s.n.

Chicago

Akmajian, Adrian, and Frank Heny. Natural Language and Linguistic Theory. s.l.: s.n., n.d.