TY - JOUR PB - American Physical Society ID - 10.1103/Physics.2.20 TI - Classifying multiferroics: Mechanisms and effects JF - Physics JA - Physics J1 - PHYSICS VL - 2 IS - SP - 20 EP - PY - 2009/03/09/ UR - http://link.aps.org/doi/10.1103/Physics.2.20 A1 - Khomskii, Daniel ER -