Where can I find technical info on USAF "drop tanks"?

…it’s pretty much all there in the title.

The kind of info I’m looking for would be; how many types of drop tanks are currently used for military aircraft (Not just the USAF, really); what are the weights, full and empty, for the various drop tank models; and what are the rough dimensions (length, width, etc) for said models (photographs would be nice, too)?

Here is a site by one of the major suppliers of external tanks: Sargent Fletcher Inc.