one study was done in the Southern Medical Journal but it would have occures in 1990-1992. Sorry I don't have the full citation. I do remember the article dealt with your topic. Linda Butson Bitnet: 3lhpsa3@CMUVM Off-Campus Librarian Internet: [log in to unmask] Central Michigan University Phone: (703) 849-8248 8110 Gatehouse Road Suite 500 W Fax: (703) 849-8254 Falls Church, VA 22042