What was found
SUPPLEMENTAL INFORMATION: FLT 1037, SJU-SDQ. RETURNED TO FIELD. OVERWHELMING DIRTY SOCK ODOR AFTER TAKEOFF. WE BOTH FELT NAUSEOUS AND HAD HEADACHES. INFLIGHT DID NOT SMELL IT IMMEDIATELY, BUT DID AFTER ABOUT 5 MINS; PERFORMED OPERATIONAL CHECK REF 71-00-01 ALSO ACCOMPLISHED PROCEDURES ON AIRCRAFT FIM 21-20-00-810-801A. NO ABNORMAL ODOR DETECTED WITH ENGINES AND /OR APU BLEEDSOURCES. A/C IS GOOD TO CONTINUE SERVICE.