Thanks for those who have helped with this search. I have a done an
office-based lit. review and have not found very much at all, to which I
am very surprised.
Here is what I have so far.

BIRDS OF A FEATHER: Homophily in Social Networks   Miller McPherson,
Smith-Lovin, James M Cook   Annual Review of Sociology Aug 2001, Vol.

Mehra, Kilduff, & Brass, 1998.  At the margins: A distinctiveness
approach to the social identity and social networks of underrepresented
groups.  Academy of Management Journal, 41: 441-452.

1993, Stephenson, K.A. and Krebs, V. "A More Accurate Way to Measure
Diversity," Personnel Journal, 72, 10, 66-74.

Erickson, Bonnie (1996). Culture, Class and Connections. American
Journal of
Sociology, 102: 217-251.