00438naa a2200157 a 450000100080000000500110000800800410001910000190006024500560007926000090013565300160014465300110016065300080017170000180017977300830019710475662006-08-03       1988    bl ---       0--  u    #d1 aTHURMAN, W. N.  aChickens, eggs, and causality, ou which came first?  c1988  aCasualidade  aFranco  aOvo1 aFISHER, M. E.  tAmerican Journal of Agricultural Economicsgv. 70, n. 2, p.237-238, may, 1988.