Traffic in opium and other dangerous drugs : conference for the adoption of a protocol to extend to dihydrocodeine and its salts certain provisions of the Convention for limiting the manufacture and regulating the distribution of narcotic drugs, July 13th, 1931 : replies from governments to the Secretary-General's letter of Febraury 19th, 1938 (C.L.20.1938.XI)
League of Nations.
Geneva : League of Nations,
1939.
Caption title.
"Official no.: Conf. Dihydrocodeine. 1."
"Geneva, February 9th, 1939."