Physics Letters A
Physics Letters A > 2010 > 374 > 4 > 557-561
Physics Letters A > 2010 > 374 > 4 > 544-551
Physics Letters A > 2010 > 374 > 13-14 > 1440-1449
Physics Letters A > 2010 > 374 > 34 > 3441-3446
Physics Letters A > 2010 > 374 > 38 > 3932-3941