Betti group

In a broad sense, the same as a homology group; in a narrow sense, the Betti group is the free part of the homology group with as domain of coefficients the group $\ZZ$ of integers, if this homology group is finitely generated. Named after E. Betti (1823–1892).

References

[1]	H. Seifert, W. Threlfall, "A textbook of topology" , Acad. Press (1980) (Translated from German)
[2]	P.S. Aleksandrov, "An introduction to homological dimension theory and general combinatorial topology" , Moscow (1975) (In Russian)
[a1]	E.H. Spanier, "Algebraic topology" , McGraw-Hill (1966)