Department of Mathematics,
University of Zagreb,
Bijenička 30, 10000 Zagreb,
Croatia

*e-mail:* `gmuic@math.hr`

**Abstract.** In this paper we study birational maps of modular curve *X(1)* attached to *SL _{2}(Z)* into the projective plain

**2010 Mathematics Subject Classification.**
14H50, 11F11, 11F23.

**Key words and phrases.** Modular forms, modular curves, birational equivalence.

DOI: 10.3336/gm.48.2.06

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