Refs on Gender variation in written text?

[Shlomo Argamon]

I'm a researcher in automatic text classification, and I've been doing
some work (with colleagues) on distinguishing texts written by male authors
from those written by females (in English).  We can currently distinguish
author gender at an accuracy of about 72% using content-free lexical items
(pronouns, prepositions, etc.).  We'd be very interested in hearing about
any other work out there on gender differences in written texts.  Most
of the sociolinguistic work on gender seems to be on features of spoken
text - phonology, discourse structure, and so forth.  Can anyone recommend
work on gender and written text?

Thanks,
       Dr. Shlomo Argamon
       Bar-Ilan University
       Jerusalem College of Technology