1 - The Physical Review, A Journal of Experimental & Theoretical Physics, conducted by the American Physical Society, Volume IV, Second Series, July 1914, blue fabric spine tan marbled boards, original paper wrapper, Internally fine and clean, first edition of Robert Andrews Millikan's paper, A Direct Determination of "h" [p.73 - p.75] and, Effect of Residual Gases on Contact EMF's and Photo-Currents [p.73]

2 - The Physical Review, A Journal of Experimental & Theoretical Physics, conducted by the American Physical Society, Volume VIII, Second Series, July 1916, blue fabric spine tan marbled boards, original paper wrapper, Internally fine and clean, first edition of Robert Andrews Millikan's paper, The Existance of a Subelectron? [p.595 - p.625]

3 - Nature Magazine, A Weekly Illustrated Journal of Science, Saturday March 21, 1925, unbound journal, first edition of Robert Andrews Millikan's paper, Series Spectra of Twopvalence-electron systems and of Three-valence-electron Systems [p.422 - p.433]

4 - The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Vol.48, August 1924, No.284, first edition of Robert Andrews Millikan's paper: the fine structure of the Nitrogen, Oxygen and Fluorine lines in the extreme ultraviolet. [p.259 - p.264] Complete journal

Note: (1) this is the first edition of the early work that led Millikan to the determination of Planck´s constant (h). It was Einstein who in 1921 was awareded the Nobel prize in Physics for his work on the photoelectric effect with Millikan awarded the Physics Nobel Prize in 1923 “for his work on the elementary charge of electricity and on the photoelectric effect".

From the American Physical Society - "In 1915, Millikan experimentally verified Einstein's all-important photoelectric equation, and made the first direct photoelectric determination of Planck's constant h. Einstein’s 1905 paper proposed the simple description of ‘light quanta,’ or photons, and showed how they explained the photoelectric effect. By assuming that light actually consisted of discrete energy packets, Einstein proposed a linear relationship between the maximum energy of electrons ejected from a surface, and the frequency of the incident light. The slope of the line was Planck’s constant, introduced 5 years earlier by Planck. Millikan was convinced that the equation had to be wrong, because of the vast body of evidence that had already shown that light was a wave. If Einstein was correct, his equation for the photoelectric effect suggested a completely different way to measure Planck's constant.

“Millikan undertook a decade-long experimental program to test Einstein's theory by careful measurement of the photoelectric effect, and even devised techniques for scraping clean the metal surfaces inside the vacuum tube needed for an uncontaminated experiment.

“For all his efforts Millikan found what to him were disappointing results: he confirmed Einstein's predictions in every detail, measuring Planck's constant to within 0.5% by his method. But Millikan was not convinced of Einstein's radical interpretation, and as late as 1916 he wrote, ‘Einstein's photoelectric equation... cannot in my judgment be looked upon at present as resting upon any sort of a satisfactory theoretical foundation,’ even though ‘it actually represents very accurately the behavior’ of the photoelectric effect. He received the Nobel Prize in part for this discovery nonetheless"