Birk, W. O. (1949). Structural grammar for building sentences. D.C. Heath.
Chicago-viite (17. p.)Birk, William Otto. Structural Grammar for Building Sentences. Boston: D.C. Heath, 1949.
MLA-viite (9. p.)Birk, William Otto. Structural Grammar for Building Sentences. D.C. Heath, 1949.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.