%0 Journal Article %A Mikhail V. Safonov %A Yu Yuan %T Doubling properties for second order parabolic equations. %J Annals of mathematics %D 1999 %V 150 %N 1 %U http://geodesic.mathdoc.fr/articles/10.2307/121104/ %R 10.2307/121104 %F 10_2307_121104