According to my subscription agent's computer files, the 1993 edition came
out in March of this year.  You may need to contact the publisher directly
to confirm this information. (I've had to contact publishers many times to
get publication date information when my agent had no idea and then give
the information to my agent.)

M.E. Sharpe Inc
80 Business Park Dr
Armonk, NY  10504
(914) 273-1800

Good luck!

Doug Jonas                       Southfield Public Library
Serials Clerk                    26000 Evergreen Road
jonasdou@metronet.lib.mi.us      Southfield MI  48076
                                 (248) 948-0461