Neue Beiträge zur Kenntnis der Permischen Echinodermen von Timor. I. Allagecrinus, II. Hypocrinites.
1929. Dienst Mijnb. Ned.-Ind. Wetensch. Meded. 11; 116 pp. 16 fig. 7 plts. h.t. Orig. wrps. lower margin of cover with moist stain, but not inside, pages wit brown spots, plates very good, in all a good copy.
Neue Beiträge zur Kenntnis der permischen Echinodermen von Timor VII. Die anomalien der Schizoblasten.
1932. Reprint Dienst Mijnb. Ned.-Ind. Wetensch. Meded. 20; pp. 5-37, 4 plts. h.t. Orig. wrps. with handwritten presentation of the author to H.A. Brouwer, cover margins a bit frayed in places, otherwise very good.