00698cam a22002171  45000010008000000030008000080050017000160080041000330100017000740400027000910500014001180820013001321000020001452450103001652600036002683000026003044900034003305040051003646500031004157000034004463114789BD-DhUL20160407201315.0711012s1966    ilu      b    000 0 eng    a   66010806   aDLCcDLCdDLCdBD-DhUL00aH62b.W3800a307bWEU  aWebb, Eugene J.00aUnobtrusive measures :cEugene J. Webb [and others]bnonreactive research in the social sciences /  aChicago :bRand McNally;c1966.  axii, 225 p. :c22 cm.0 aRand McNally sociology series  aIncludes bibliographical references and index. 0aSocial sciencesxResearch.  aCampbell, Donald T. [et. all]