Lefschetz, S. (1942). Algebraic topology. American Mathematical Society.
Lua i Stíl Chicago (17ú heag.)Lefschetz, Solomon. Algebraic Topology. New York: American Mathematical Society, 1942.
Lua MLA (9ú heag.)Lefschetz, Solomon. Algebraic Topology. American Mathematical Society, 1942.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.