@article{10_4064_fm223_3_1,
     author = {Rafa{\l} Lutowski and Andrzej Szczepa\'nski},
     title = {Holonomy groups of flat manifolds with the $R_{\infty} $ property},
     journal = {Fundamenta Mathematicae},
     pages = {195--205},
     publisher = {mathdoc},
     volume = {223},
     number = {3},
     year = {2013},
     doi = {10.4064/fm223-3-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm223-3-1/}
}