@article{10_4007_annals_2015_182_2_1,
     author = {Max Lieblich},
     title = {The period-index problem for  fields of transcendence degree $2$},
     journal = {Annals of mathematics},
     pages = {391--427},
     publisher = {mathdoc},
     volume = {182},
     number = {2},
     year = {2015},
     doi = {10.4007/annals.2015.182.2.1},
     mrnumber = {3418522},
     zbl = {06487144},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4007/annals.2015.182.2.1/}
}