[1] A. A. Albert, Modern higher algebra, Chicago 1936.
[2] S. C. Chang, On algebraic structures and homotopy invariants, Bulletin de l'Académie Polonaise des Sciences Classe III, 4 (1956), p. 797-800.
[3] S. C. Chang On proper isomorphisms of (μ, Δ, γ)-systems, I, ibidem, p. 113-118. (Complete exposition (Chinese) [3'], Acta Mathematica Sinica 6 (1956), p. 270-301).
[4] S. C. Chang On proper isomorphisms of (μ, Δ, y)-systems, II, Acta Mathematica Sinica 6 (1956), p. 295-308 (Chinese).
[5] S. C. Chang On homotopy types and homotopy groups of polyhedra, I, II, Science Record, Academia Sinica I (1957), pp. 205-208, 209-213.
[6] S. C. Chang Homotopy invariants and continuous mappings, Proceedings of the Royal Society 202 (1950), p. 253-263.
[7] S. C. Chang and J. H. C. Whitehead, Note on cohomology systems, Quarterly Journal of Mathematics (2), 2 (1951), p. 167-174.
[8] K. Shiraiwa, On the homotopy type of an $А^3_n$-polyhedron (n ≥ 3), American Journal of Mathematics 76 (1954), p. 235-251.