1. On the influence of distilled water and lithium chloride upon the eggs of Limnaea stagnalis L. at the 2-cell stage;Raven,1950
2. An investigation into the earlier vegetation of Central Friesland (the Netherlands);Van Zeist;Recl. Trav. Bot. Néerl.,1949
3. Kalanchoë blossfeldiana treated with 2.3.5.triiodobenzoic acid (Tiba);Van Zeist,1951
4. Groeistof bepalingen bij hogere planten;Van Zeist;Meded. Dir. Tuinbouw,1951
5. Zur Datierung einer Moorleiche;Van Zeist;Acta Bot. Neerl.,1953