TY - JOUR T1 - The non-declared vote in the surveys: The Spanish case in the 1980s AU - Urquizu-Sancho, Ignacio PY - 2006 DO - 10.1016/j.electstud.2005.03.008 SP - 103 EP - 128 JO - Electoral Studies VL - 25 IS - 1 SN - 0261-3794 ER -