RT Book, Section SR Electronic(1) A1 United Nations YR 1982 T1 Conversion coefficients and factors T2 Statistical Yearbook 1979-1980, Thirty-first Issue PB United Nations SN 9789210452960 DO 10.18356/ac0f88a8-en-fr UL https://www.un-ilibrary.org/content/books/9789210452960s029-c002