1. Anderson M. (1991). Remarks on the compactness of isospectral sets in low dimensions. Duke Math. J., 63, 699–711.
2. Anikonov
Yu. E. and Romanov V.G. (1976). On uniqueness of definition of first-order form by its integrals over geodesies. Ill-posed Math, and Geophys. Problems. Novosibirsk, 22–27 (in Russian).
3. Anosov D. (1967). Geodesic Flows on Closed Riemannian Manifolds with Negative Curvature, Proc. Steclov Inst, of Math., Vol. 90.
4. Anosov D.V. (1985). On geodesic flows satisfying the condition (Y).Proc. Steclov Inst, of Math., 167, 3–24.
5. Arbuzove V., Bukhgeim A.L., and Kazantsev S.G. (1998). Two-dimensional tomography problems and the theory of A-analytic functions. Siberian Adv. Math., 8, 1–20.