Harry Buhrman Lance Fortnow Rahul Santhanam Unconditional Lower Bounds against Advice. 195-209 2009 ICALP (1) http://dx.doi.org/10.1007/978-3-642-02927-1_18 conf/icalp/2009-1 db/conf/icalp/icalp2009-1.html#BuhrmanFS09