Subjects: “…., Engels, Friedrich., Fourth International., Group portrait.]…”

“…Second World Congress of the Fourth International. Names on back.…”

“…President of the fourth international congress for sexual reform and sexuology in Vienna, 1930, September 16 to 23.…”

“…Ta-thu-Thau was a Vietnamese Trotskyist and the leader of the Fourth International in Vietnam. Enclosed two copies with handwritten note.…”