TY - JOUR AU - Carroll, Joseph E. TI - On determining the quadratic subfields of $Z_2$-extensions of complex quadratic fields JO - Compositio Mathematica PY - 1975 SP - 259 EP - 271 VL - 30 IS - 3 PB - Noordhoff International Publishing UR - http://archive.numdam.org/item/CM_1975__30_3_259_0/ LA - en ID - CM_1975__30_3_259_0 ER -