Stallings, John, Groups of cohomological dimension one, Applications of Categorical Algebra (Proc. Sympos. Pure Math., Vol. XVIII, New York, 1968), Providence, R.I.: Amer. Math. Soc.: 124–128, 1970, MR 0255689. 特別見p. 126: "If G has two ends, the explicit structure of G is well known: G is an extension of a finite group by either the infinite cyclic group or the infinite dihedral group."
Alonso, J. M.; Brady, T.; Cooper, D.; Ferlini, V.; Lustig, M.; Mihalik, M.; Shapiro, M.; Short, H., Notes on word hyperbolic groups, Group theory from a geometrical viewpoint (Trieste, 1990)(PDF), River Edge, NJ: World Scientific, Corollary 3.6, 1991 [2014-04-01], MR 1170363, （原始内容(PDF)存档于2013-04-25）
books.google.com
Stallings, John, Groups of cohomological dimension one, Applications of Categorical Algebra (Proc. Sympos. Pure Math., Vol. XVIII, New York, 1968), Providence, R.I.: Amer. Math. Soc.: 124–128, 1970, MR 0255689. 特別見p. 126: "If G has two ends, the explicit structure of G is well known: G is an extension of a finite group by either the infinite cyclic group or the infinite dihedral group."
univ-mrs.fr
cmi.univ-mrs.fr
Alonso, J. M.; Brady, T.; Cooper, D.; Ferlini, V.; Lustig, M.; Mihalik, M.; Shapiro, M.; Short, H., Notes on word hyperbolic groups, Group theory from a geometrical viewpoint (Trieste, 1990)(PDF), River Edge, NJ: World Scientific, Corollary 3.6, 1991 [2014-04-01], MR 1170363, （原始内容(PDF)存档于2013-04-25）
web.archive.org
Alonso, J. M.; Brady, T.; Cooper, D.; Ferlini, V.; Lustig, M.; Mihalik, M.; Shapiro, M.; Short, H., Notes on word hyperbolic groups, Group theory from a geometrical viewpoint (Trieste, 1990)(PDF), River Edge, NJ: World Scientific, Corollary 3.6, 1991 [2014-04-01], MR 1170363, （原始内容(PDF)存档于2013-04-25）
