@article{10_4064_cm112_2_3,
     author = {Roger Clement Crocker},
     title = {On the sum of two squares and two powers of $k$},
     journal = {Colloquium Mathematicum},
     pages = {235--267},
     publisher = {mathdoc},
     volume = {112},
     number = {2},
     year = {2008},
     doi = {10.4064/cm112-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm112-2-3/}
}