which city located on 2011 firs men's roller hockey world cup is also the stadium 2011–12 olympiacos f . c . season ?
SELECT DISTINCT var_uri where brack_open dbr_2011–12_Olympiacos_F.C._season dbp_stadium var_uri sep_dot dbr_2011_FIRS_Men's_Roller_Hockey_World_Cup dbp_cities var_uri brack_close