Levin, O. (2016). Discrete mathematics: An open introduction (2nd edition.). [publisher not identified].
Chicago-viite (17. p.)Levin, Oscar. Discrete Mathematics: An Open Introduction. 2nd edition. [Place of publication not identified]: [publisher not identified], 2016.
MLA-viite (9. p.)Levin, Oscar. Discrete Mathematics: An Open Introduction. 2nd edition. [publisher not identified], 2016.
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