00294nam a2200121Ia 4500020001500000082002400015100001700039245005600056260003700112300001300149500000500162700000500167  a0485195461  a338.109861bOr77.UP  aOrtiz, S. R.  aUncertainities in peasant farmingba Colombian case  aNew YorkbHumanities Pressc1973  ax, 294p.  a  a