BUREAU OF INDIAN STA AMENDMENT NO 1 JULY 1985 TO IS : 1891 ( PART 4 ) 1978 SPECIFIATION FOR RUBBER CONVEYOR AND ELEVATOR - 1st rev. 1985 - NEW DELHI BUREAU OF INDIAN STANDARDS. - 3 Subjects--Topical Terms: RUBBER CONVEYOR AND ELEVATOR BELTING Dewey Class. No.: 621 / BUR