Published occasionally with parallel title: Mundo obrero, June 24, 1977-<May 19, 1978>
At head of title: "Black and white unite for a ... ", <Apr. 26, 1963-Oct. 16, 1970>, and: "Workers and oppressed peoples of the world unite", <Jan. 15, 1971-Sept. 1, 1983>.
Description based on: Vol. 23, no. 33 (Aug. 14, 1981); title from cover.
Latest issue consulted: Vol. 28, no. 47 (Nov. 28, 1986).
Occasionally published in English and Spanish, Jan. 19-Nov. 2, 1973, and: June 24, 1977-<May 19, 1978>.
Issued 19 - by Workers World Party.