David Eppstein,
Mark Overmars,
Günter Rote,
and Gerhard J. Woeginger
Discrete & Computational Geometry 7(1):45–58, 1992
Mathematical Reviews 92k:52026
http://www.ics.uci.edu/~eppstein/pubs/EppOveRot-DCG-92.pdf
Cited by:
Early drafts of this (before the merger with Overmars et al) used the title "Finding the smallest quadrilateral".