00311nam a2200097Ia 4500008004100000040001100041245008400052260005000136300001700186300001000203251112s9999||||xx |||||||||||||| ||und||  aCNCLSA 0aProceedings of the National Academy Of Sciences of the United States of America  cAugust 1, 1992bProc. Natl. Acad. Sci.aU.S.A  aP. 6665-7850  bV. 89