TY - JOUR AU - John C. Baez AU - Alissa S. Crans AU - Urs Schreiber AU - Danny Stevenson TI - From loop groups to 2-groups JO - Homology, homotopy, and applications PY - 2007 SP - 101 EP - 135 VL - 9 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.4310/HHA.2007.v9.n2.a4/ DO - 10.4310/HHA.2007.v9.n2.a4 LA - en ID - HHA_2007_9_2_a4 ER -