@article{10_4064_aa166_4_4,
     author = {Kenneth S. Williams},
     title = {Ternary quadratic forms $ax^2+by^2+cz^2$
 representing all positive integers $8k+4$},
     journal = {Acta Arithmetica},
     pages = {391--396},
     publisher = {mathdoc},
     volume = {166},
     number = {4},
     year = {2014},
     doi = {10.4064/aa166-4-4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa166-4-4/}
}