@article{JLT_2003_13_1_JLT_2003_13_1_a13,
     author = {P. Graczyk and P. Sawyer },
     title = {The {Product} {Formula} for the {Spherical} {Functions} on {Symmetric} {Spaces} of {Noncompact} {Type}},
     journal = {Journal of Lie theory},
     pages = {247--261},
     publisher = {mathdoc},
     volume = {13},
     number = {1},
     year = {2003},
     url = {http://geodesic.mathdoc.fr/item/JLT_2003_13_1_JLT_2003_13_1_a13/}
}