TY - JOUR AU - Balmer, Paul AU - Dell’Ambrogio, Ivo AU - Sanders, Beren TI - Restriction to finite-index subgroups as étale extensions in topology, KK–theory and geometry JO - Algebraic and Geometric Topology PY - 2015 SP - 3023 EP - 3045 VL - 15 IS - 5 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2015.15.3025/ DO - 10.2140/agt.2015.15.3025 ID - 10_2140_agt_2015_15_3025 ER -