@article{1181070022,
author = {Hjorth, Greg},
title = {Measuring the Classification Difficulty of Countable Torsion-Free Abelian Groups},
journal = {Rocky Mountain J. Math.},
volume = {32},
number = {4},
year = {2002},
pages = { 1267-1280},
language = {en},
url = {http://dml.mathdoc.fr/item/1181070022}
}
Hjorth, Greg. Measuring the Classification Difficulty of Countable Torsion-Free Abelian Groups. Rocky Mountain J. Math., Tome 32 (2002) no. 4, pp. 1267-1280. http://gdmltest.u-ga.fr/item/1181070022/