1. Einstein, A., Ann. Phys. ,Leipzig 17, 132–148 (1905).
2. de Broglie, L., Recherches sur la théorie des quanta, Doctoral thesis, University of Paris 1924.
3. Barrow, J. D., Quart. F. R. Astr. Soc. 24, 24–26 (1983).
4. Stoney, G. J., Phil. Mag. ,Ser. 5, 381–390 (1881).
5. Kostro, L., “A deduction of natural units,” unpublished paper, 1986.