000			00543nam a2200157 a 4500
005			20220228110620.0
035			_aF8901000708630
084			_aPCA BUL 172 1964
100			_aRoper, Harold.
245			_aPetrographic studies on concrete containing shrinking aggre-gate / by Harold Roper, J. E. Cox and Bernard Erlin.
260			_aSkokie, Illinois : atories
300			_a[18] p.
440			_aBulletin 172 / Portland Cement Association
690			_aConcreto - Análisis petrográfico.
700			_aCox, J. E., coaut.Erlin, Bernard, coaut.
999			_c58715 _d58715