TY  - DATA
AU  - Beaumont, Ross A.
AU  - Pierce, Robert Stanley.
TI  - Torsion free groups of rank two 
T2  - Memoirs of the American Mathematical Society, 
SN  - 9780821899816 (online)
PY  - 1961///
CY  - Providence, R.I.
PB  - American Mathematical Society
UR  - http://www.ams.org/memo/0038
ER  -