The Dust Charging Equation from OML Theory

I have come across the following paper (PF 5, 737, 1962) which appears to be the first derivation of the dust charging equation using OML theory. In Rosen's paper, the usual "Z" is denoted by "N", n_p denotes the dust density, and "a" is the radius of the dust particle. He also assumes from the outset that the charge is negative. The charging equation is the third equation in the right hand column on page 737. By using the charge neutrality condition, he also obtains the charging equation that takes into account the close-packing effect. This paper was published as a research note and contains no abstract or keywords, or PACS numbers. The title of the paper ("Method for the removal of free electrons in a plasma") also does not mention dust. It is likely for these reasons, that this paper has not been noticed by the dusty plasma community.