@article{10_4064_cm_64_1_41_54,
     author = {Wojciech M{\l}otkowski},
     title = {Type-dependent positive definite functions on free products of groups},
     journal = {Colloquium Mathematicum},
     pages = {41--54},
     publisher = {mathdoc},
     volume = {64},
     number = {1},
     year = {1993},
     doi = {10.4064/cm-64-1-41-54},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-64-1-41-54/}
}