[78-L] Mexican 78's - 1930's to 1950's. A discography?

[James]

Does anyone know if a discography covering Mexican 78's exists. I have a 
nice bunch on Bluebird, RCA, Peerless, Taxco, Musart.....and others and 
would love more info about them. Most of my collection is from the mid 
1930's to the early 1950's. Based on some cursory internet searches, 
there appears to be little out there. Even information on the various 
labels that catered to Mexico would be nice.

Thanks for any help!