1. The Constancy of Spectral Line Excitation in Quantitative Spectrographic Analysis;Llewellyn Jones;J.S.C.I.,1945
2. A Photographic Method of Measuring the Relative Intensities of Spectral Lines;Duffendack;J. Opt. Soc. Amer.,1933
3. Analysis of Caustic Liquors for Traces of Impurities;Duffendack;Ind. Eng. Chem. (Anal.),1938