Baldwin, J. M. (1906). Thought and Things. London, 3 vols.
Baylis, W. E. (1993). Electrons, photons, and spinors in the Pauli algebra. in: Z. Oziewicz et al. (eds), Spinors, Twistors, Clifford Algebras and Quantum Deformations, Dordrecht, pp. 97–106.
Belger, M. & Ehrenberg, L. (1981). Theorie und Anwendung der Symmetriegruppen. Frankfurt am Main.
Clark, G. (1989). New light on Peirce's iconic notation for the sixteen binary connectives. Paper presented at the Sesquicentennial Congress at Harvard University.
Clark, G. & Zellweger, Sh. (1993). Let the mirrors do the thinking. Mount Union Magazine, Spring: 2–5.
Flusser, V. (1992). Die Schrift. Frankfurt am Main.
Fuller, R. Buckminster. (1975). Synergetics: Explorations in the Geometry of Thinking. New York.
Kiss, S. A. (1947). Transformations on Lattices and Structures of Logic. New York.
Laing, R. D. (1976). The Facts of Life. New York.
Lounesto, P., Mikkola, R., & Vierros, V. (1987). CLICAL User Manual — Complex Number, Vector Space and Clifford Algebra Calculator for MS-DOS Personal Computers. Helsinki.
Menger, K. (1962). A group in the substitutive algebra of the calculus of propositions. Archiv der Mathematik 13: 471–478.
Peirce, Ch. S. (1902). The simplest mathematics. in: C. Hartshorne, & P. Weiss (eds), Collected Papers of Charles Sanders Peirce. Cambridge, vol 4, pp. 227–323.
Petraschen, M. I. & Trifonow, E. D. (1969). Anwendung der Gruppentheorie in der Quantenmechanik. Leipzig.
Piaget, J. (1957). Logic and Psychology. New York.
Schmeikal-Schuh, B. (1989). Soziogene der Orientierung — Ikonen der Raumzeit. WISDOM. Jg. III, 3/4: 1–18.
Schmeikal-Schuh, B. (1993). Logic from space. Quality & Quantity 27: 117–137.
Schmeikal, B. (1993). Space-time Sociology. Vienna, Research-Memorandum, Nr. 313.
Schmeikal, B. (1995). The implicate order of the void. Internal paper of the Biofield Laboratory, Vienna.
Schmeikal, B. (1996). The generative process of space-time and strong interaction, quantum numbers of orientation, in: R. Ablamowicz, P. Lounesto, & J. M. Parra (eds), Clifford Algebras with Numeric and Symbolic Computations. Boston, pp. 83–100.
Zellweger, Sh. (1982). Sign-creation and man-sign engineering, Semiotica 38,1/2: 17–54.
Zellweger, Sh. (1987). Notation, Relational Iconicity, and Rethinking the Propositional Calculus. 8th International Congress of Logic, Methodology and Philosophy of Science. Moscow.
Zellweger, Sh. (1992). Cards, Mirrors and Hand Held Models that Lead into Elementary Logic, Sixteenth Annual Conference of the International Group for the Psychology of Mathematics Education. University of New Hampshire.