"Back And Forth" title contains a sample of Black Sabbath "Changes" song starting at 0'40''. Depending of wich version you have of the record I suppose, because this sample is not present in my LP "Mo Wax – MWU 001LP, Island Records – 986 554-8" You can hear it there : http://www.whosampled.com/sample/57395/Unkle-Back-and-Forth-Black-Sabbath-Changes/