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." نسخة محفوظة 26 مارس 2015 على موقع واي باك مشين.
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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." نسخة محفوظة 26 مارس 2015 على موقع واي باك مشين.
