1. T. Levi-Cività, “Sulle transformationi delle equazioni dinamiche,” Ann. Math. Milano, Ser. 2, 24 (1894), 255–300.
2. T. Y. Thomas, “On projective and equiprojective geometries of paths,” PWC Nat. Acad. Sci. USA, 11 (1925), 198–203.
3. H. Weyl, “Zur Infinitesimalgeometrie Einordnung der projectiven und der conformen Auffassung,” Göttingen Nachr. (1921), 99–112.
4. N. S. Sinyukov, Geodesic Maps of Riemannian Spaces [in Russian], Nauka, Moscow, 1979.
5. W. J. Westlake, “Hermitian spaces in geodesic correspondence,” Proc. Amer. Math. Soc., 5 (1954), no. 2, 301–303.