Avron, J.; Grossmann, A.; Rodriguez, R. (1974). "Hamiltonians in one-electron theory of solids. I.". Reports on Mathematical Physics. 5 (1): 113–120. doi:10.1016/0034-4877(74)90020-2.
Katsuda, A.; Sunada, T (1987). "Homology and closed geodesics in a compact Riemann surface". Amer. J. Math. 110 (1): 145–156. doi:10.2307/2374542. JSTOR2374542.
Katsuda, A.; Sunada, T (1987). "Homology and closed geodesics in a compact Riemann surface". Amer. J. Math. 110 (1): 145–156. doi:10.2307/2374542. JSTOR2374542.