1. Birkhoff, G., ?Lattices in Applied Mathematics?, in R. P. Dilworth (ed.), Lattice Theory, American Mathematical Society, Providence, R.I., 1961.
2. Burnside, W., Theory of Groups of Finite Order, Dover, New York, 1955. (Original edition 1897.)
3. Dacey, J. C., Jr., Orthomodular Spaces, Unpublished Ph.D. dissertation, University of Massachusetts, Amherst, 1968.
4. Dirac, P. A. M., The Principles of Quantum Mechanics (4th ed.), Oxford University Press, London, 1958. (Original edition 1930.)
5. Foulis, D. J., ?A Note on Orthomodular Lattices?, Portugaliae Mathematica 21 (1962), 65?72.