1. M. Atiyah, Riemann surfaces and spin structures, Ann. Scient. ÉNS 4 e Série, 4 (1971), 47–62.
2. E. Calabi, An intrinsic characterization of harmonic 1-forms, Global Analysis, Papers in Honor of K. Kodaira, D. C. Spencer and S. Iyanaga (ed.), pp. 101–117, 1969.
3. A. Eskin, H. Masur, Asymptotic formulas on flat surfaces, Ergodic Theory and Dynamical Systems, 21 (2) (2001), 443–478.
4. A. Eskin, A. Zorich, Billiards in rectangular polygons, to appear.
5. A. Eskin, A. Okounkov, Asymptotics of number of branched coverings of a torus and volumes of moduli spaces of holomorphic differentials, Invent. Math., 145 (1) (2001), 59–104.