TY - JOUR AU - Amir Levinson AU - Mitchell Begelman BT - The Astrophysical Journal DA - 2013-02 DO - 10.1088/0004-637X/764/2/148 PY - 2013 EP - 148 T2 - The Astrophysical Journal TI - Collimation and Confinement of Magnetic Jets by External Media VL - 764 SN - 0004-637X ER -