@article{10_4064_fm204_1_1,
     author = {Piotr Niemiec},
     title = {Urysohn universal spaces as metric groups of exponent 2},
     journal = {Fundamenta Mathematicae},
     pages = {1--6},
     year = {2009},
     volume = {204},
     number = {1},
     doi = {10.4064/fm204-1-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm204-1-1/}
}