00321nam a2200109 a 450000500170000008200170001710000230003424500260005726000530008330000250013650000500016120251203090710.0  a577.582bBIO  aBoucher,Douglas H.  aBiologty of mutualism  aNew DelhibInternational Books periodicalsc1985  avii,388p.c22cm.bHB  aincludes bibliographical references and index