00581cam a2200217 4500 sa 68019129 DLC 20260227112717.0 711122s1968 ii abh 00000 eng sa 68019129 //r862 PL480:I-E-10897 a-ii--- QC51.I42 N376 530/.07/205456 National Physical Laboratory (India) NPL, 1968. New Delhi [1968] 56 p. illus., facsims., map. 27 cm. Cover title. National Physical Laboratory (India) 88834 88834