@article{KJM_2005_28_1_a8,
     author = {Peter B. Gilkey and Stana \v{Z}. Nik\v{c}evi\'c},
     title = {Generalized plane wave manifolds},
     journal = {Kragujevac Journal of Mathematics},
     pages = {113 - 138},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {2005},
     zbl = {1143.53337},
     url = {http://geodesic.mathdoc.fr/item/KJM_2005_28_1_a8/}
}