@article{MS2_1991__68_1_167144,
     author = {J\"org Br\"udern},
     title = {Ternary additive problems of {Waring's} type.},
     journal = {Mathematica Scandinavica},
     pages = {27--45},
     publisher = {mathdoc},
     volume = {68},
     number = {1},
     year = {1991},
     zbl = {0759.11031},
     url = {http://geodesic.mathdoc.fr/item/MS2_1991__68_1_167144/}
}