On opium and opium preparations, especially on opium extract and opium concentration = Oopiumist ja oopiumipreparaatidest, eriti oopiumiekstraktist ja oopiumkontsentraadist

von Kuusik, Ulrich
Tartus : Varrak, 1939

American trade in opium to China in the nineteenth century

von Stelle, Charles Clarkson; Stelle, Charles Clarkson
In: The Pacific Historical Review, volume 9, (December, 1940); volume 10 (March, 1941) (1941) Berkeley, Calif. [u.a.] : University of California Press, 1941