What was found
ON APPROACH, WHEN GEAR WAS EXTENDED, NOSE GEAR DOWN INDICATION FAILED TO ILLUMINATE. CREW CONTACTED ATC AND ABORTED APPROACH TO WORK AFM CHECK LIST FOR GEAR PROBLEM. STILL UNABLE TO GET GEAR DOWN INDICATION, CREW DECLARED EMERGENCY, BLEW GEAR DOWN AND LANDED WITHOUT INCIDENT. MAINTENANCE FOUND BOTH NOSE GEAR ANNUNCIATOR BULBS INOPERATIVE. BULBS WERE REPLACED, EMERGENCY GEAR BOTTLE WAS RESET AND SERVICED, GEAR RETRACTION SYS FUNCTIONALLY CHECKED SATISFACTORY AND AC RETURNED TO SERVICE.