Hess, A. L. (1977). Four-dimensional geometry: An introduction. National Council of Teachers of Mathematics.
Chicago-viite (17. p.)Hess, Adrien L. Four-dimensional Geometry: An Introduction. Reston, VA: National Council of Teachers of Mathematics, 1977.
MLA-viite (9. p.)Hess, Adrien L. Four-dimensional Geometry: An Introduction. National Council of Teachers of Mathematics, 1977.
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