TY  - JOUR
T1  - An Apparatus for Measurements of the Defining Power of Objectives
JF  - Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character (1905-1934)
VL  - 82
IS  - 555
SP  - 307
EP  - 314
PY  - 1909/06/30/
UR  - http://dx.doi.org/10.1098/rspa.1909.0035
M3  - doi:10.1098/rspa.1909.0035
AU  - de Graaff Hunter, J.
ER  -