@article{CMUC_1994__35_4_a2,
     author = {Ton, Dao-Rong},
     title = {Free $\ell $-groups and free products of $\ell $-groups},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {617--625},
     publisher = {mathdoc},
     volume = {35},
     number = {4},
     year = {1994},
     mrnumber = {1321232},
     zbl = {0820.06010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1994__35_4_a2/}
}