%0 Journal Article %A Rohrlich, David E. %T Variation of the root number in families of elliptic curves %J Compositio Mathematica %D 1993 %P 119-151 %V 87 %N 2 %I Kluwer Academic Publishers %U http://www.numdam.org/item/CM_1993__87_2_119_0/ %G en %F CM_1993__87_2_119_0