(untitled) - Erickson, J; Neidhart, D J; VanDrie, J; Kempf, D J; Wang, X C; Norbeck, D W; Plattner, J J; Rittenhouse, J W; Turon, M; Wideburg, N; Kohlbrenner, W E; Simmer, R; Helfrich, R; Paul, D A; Knigge, M (Science, 1990)