@article {ThVe01,
AUTHOR = {Thomas, Simon and Velickovic, Boban},
TITLE = {On the complexity of the isomorphism relation for fields of finite transcendence degree},
JOURNAL = {J. Pure Appl. Algebra},
FJOURNAL = {Journal of Pure and Applied Algebra},
VOLUME = {159},
YEAR = {2001},
NUMBER = {2-3},
PAGES = {347--363},
}