@article{MM2_1994__83_3-4_155967,
     author = {Joachim Schmid},
     title = {Sums of {Fourth} {Powers} of {Real} {Algebraic} {Functions.}},
     journal = {Manuscripta mathematica},
     pages = {361--364},
     publisher = {mathdoc},
     volume = {83},
     number = {3-4},
     year = {1994},
     zbl = {0811.12001},
     url = {http://geodesic.mathdoc.fr/item/MM2_1994__83_3-4_155967/}
}