1. The major functions of the noun phrase;Andrews,1985
2. The implementation of grammatical functions in Functional Discourse Grammar;Bakker;Alfa,2007
3. Grammatical Relations: The Evidence against Their Necessity and Universality;Bhat,1991
4. Grammatical relations typology;Bickel,2010
5. Structure and Function: A Guide to Three Major Structural–Functional Theories. Part 1: Approaches to the Simplex Clause;Butler,2003