LEIDEN -- HAVERKAMP, Gerhard Christiaan ('Gerrit') (1872-1926). (Academiegebouw). N.d. Etched view from the south. 213 x 163 mm. Signed in pencil. -- Id. (Gezicht op de Zijlpoort). N.d. Etching. 273 x 395 mm. Signed in pencil. -- Id. (Molen in Leiden (molen De Valk?)). N.d. Etching. 305 x 222 mm. -- And 1 o. by the same. (4).