1. A comparative study on the recovery of the geotropic response of decapitated Avena coleoptiles by indoleacetic acid, indoleacetonitrile, and naphthylacetic acid;Anker;Proc. Kon. Ned. Ak. Wet. Amsterdam C,1954
2. The auxin concentration rule for the geotropism of Avena coleoptiles;Anker;Acta Bot. Neerl.,1956
3. Geotropism and tip regeneration of the Avena coleoptile in the presence of gibberellic acid;Anker;Acta Bot. Neerl.,1967
4. The role of tryptophane and tryptamine as IAA precursors;Thimann,1968