Brassinosteroids chemistry, bioactivity, and applications ; developed from a symposium ... at the 200th National Meeting of the American Chemical Society, Washington, D.C., August 26 - 31, 1990, and an international workshop ... at the Institute of Plant Biochemistry, Halle, Saale, Germany, October 29 - November 2, 1990 (American Chemical Soc., 1991)