References

1   Bob Carpenter. 1992. The Logic of Typed Feature Structures with Applications to Unification-based Grammars, Logic Programming and Constraint Resolution, volume 32 of Cambridge Tracts in Theoretical Computer Science. Cambridge University Press, New York. 

2   Chris Manning. 1992. Documentation for avm.sty. http://www.essex.ac.uk/linguistics/clmt/latex4ling/avms/. 

3   Carl J. Pollard and Ivan A. Sag. 1994. Head-Driven Phrase Structure Grammar. University of Chicago Press, Chicago. 
