TY - JOUR T1 - An introduction to active galactic nuclei: Classification and unification JO - New Astronomy Reviews PY - 2008/01/01 AU - Tadhunter C ED - DO - DOI: 10.1016/j.newar.2008.06.004 VL - 52 IS - 6 SP - 227 EP - 239 Y2 - 2024/12/23 ER -