Making Sense of Specifications: the Formalization of SET
   Extended Abstract by Giampaolo Bella, Fabio Massacci, Lawrence C. Paulson, and Piero Tramontano. [PDF]
   http://www.ing.unitn.it/~massacci/papers/bell-mass-paul-tram-00-IWSP.pdf

Visa - Electronic Commerce - SET
   Secure Electronic Transaction (SET) information, including links to press releases, specification files and reference implementation.
   http://www.visa.com/nt/ecomm/set/

Visa, Wells Fargo Deliver SET Alternatives
   New options for handling credit card transactions over the Web are emerging as cheaper and simpler alternatives to the dormant SET standard.
   http://www.techweb.com/wire/story/TWB19990603S0015