@article{10_4171_dm_611,
     author = {V{\'\i}t\v{e}zslav Kala and Valentin Blomer},
     title = {On the {Rank} of {Universal} {Quadratic} {Forms} over {Real} {Quadratic} {Fields}},
     journal = {Documenta mathematica},
     pages = {15--34},
     year = {2018},
     volume = {23},
     doi = {10.4171/dm/611},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/611/}
}