Harding, L. W. (1952). Functional arithmetic: Photographic interpratations, kindergarten thorugh grade eight. Brown.
Chicago-viite (17. p.)Harding, Lowry Waring. Functional Arithmetic: Photographic Interpratations, Kindergarten Thorugh Grade Eight. Dubuque, WC: Brown, 1952.
MLA-viite (9. p.)Harding, Lowry Waring. Functional Arithmetic: Photographic Interpratations, Kindergarten Thorugh Grade Eight. Brown, 1952.
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