Epistemological writings : the Paul Hertz/Moritz Schlick centenary edition of 1921 with notes and commentary by the editors / Hermann von Helmholtz ; newly transl. by Malcolm F. Lowe ; ed., with an introd. and bibliography by Robert S. Cohen and Yehuda Elkana. - Helmholtz, Hermann Ludwig Ferdinand von (1821-1894) (Boston Studies in the Philosophy of Science, 1977)