Beschrijving
S.D. van Veen, Utrecht, Kemink & Zoon, 1912, 29 pages. original paper binding/C.J. Voorhoeve, Nijmegen, H. ten Hoet, 1912, 132 pages. original paper binding, photograph portrait of Valeton as frontispiece, two brochures commemorating Josué Jean Philippe Valeton (Groningen, 14 oktober 1848 – 14 januari 1912, Utrecht) a Dutch professor at the university of Utrecht and its rector magnificus.