The following is a paper by H. Aspden published in Physics Essays, v. 1, pp. 72-76 (1988).
Abstract: The hitherto unknown role of the muon in physics is now shown to be connected with the processes of proton creation in a primordial muon field. It is possible to deduce not only the mass of the proton in relation to that of the muon, but also the mass of the muon quantum that creates the proton. The advance reported depends upon the discovery of an equation that shows that the merger of a muon pair followed by energy minimization can serve to nucleate further particle synthesis by muon merger to give a unique particle some 8.8989795 times the mass of the muon quantum involved. This leads to the creation of a proton having a mass that is a little greater than 1836.152 times the electron mass, in good accord with the measured value.
Commentary: In this paper the author set out to show how the proton-electron mass ratio can be derived theoretical from a causal theory of proton creation without requiring the reader to track through prior published work by the author. Apart from its intrinsic scientific merit, this paper has the merit of being self-contained in its presentation.
The full text of this paper may also be seen in PDF format as Paper No. 9 in the author's 1996 book Aether Science Papers which is of record in the author's website http://www.haroldaspden.com.