The Washingtonias in Israel ; 1910-1960 (Aaronsohn's Herbarium, Zikhron Ya'akov) - Oppenheimer, Heinz Reinhard 1899-1971 (s.n., 1960)
Reprinted from La-Yaaran / [Aguddat Haj-ya'ar be-Jis'rā'ēl]. Volume 10, Numero 1-4 (December 1960)