doi          = {10.1073/pnas.1411728112},
 doi          = {10.1038/ncomms7383},
 doi          = {10.1088/1367-2630/16/12/123029},
 doi          = {10.1007/s10701-010-9410-x},
 doi          = {10.1007/978-3-642-21329-8},
 doi          = {10.1007/s00220-012-1605-x},
 doi          = {10.1007/JHEP09(2012)116},
 doi          = {10.1007/978-0-387-68276-1\_21},
 doi          = {10.1088/1367-2630/12/3/033024},
 doi          = {10.1088/1367-2630/14/12/129401},
 doi          = {10.1088/1367-2630/12/3/033023},
 doi          = {10.1007/978-0-387-68276-1},
 doi          = {10.1007/BFb0071358},
 doi          = {10.1007/BF01962588},