00383nam a2200121Ia 4500008004100000022001400041040001100055100002100066245008400087260006400171300001700235300000900252251112s9999||||xx |||||||||||||| ||und||  a0027-8424  aCNCLSA  aLawrence Bogorad 0aProceedings of the National Academy Of Sciences of the United States of America  cApril 1, 1991bThe National Academy of SciencesaWashington  aP. 2613-4060  bV.41