00461nam a22001337a 4500008004100000020001500041050002300056100002100079245012100100260003800221300001500259650003300274650002000307211202b        |||||||| |||| 00| 0 eng d  a013214171X  aQH3235 b.R63 1976  aRoberts, Fred S.  aDiscrete Mathematical Models bwith applications to social, biological and environmental problems cFred S. Roberts   aNew JerseybPrentice- Hall c1976  axvi, 560p.  aBiologyvmathematical models  aSocial sciences