18960Investigacion (Ecuador)PT1993-07-13 18:00:00BT9571Investigacion (Iberoamerica)PTNT21580Investigacion agricola (Ecuador)PTNT20600Investigacion cientifica (Ecuador)PTNT18966Investigacion economica (Ecuador)PTNT18953Investigacion historica (Ecuador)PTNT27149Investigacion medica (Ecuador)PT