Considered to be pioneers of the bass - heavy techno , LFO released " Frequencies " ( 1991 ) , " Advance " ( 1996 ) , and " Sheath " ( 2003 ) .
Head entity: advance Q1950285 21
Tail entity: sheath Q1947434 29
Relation (head \u2192 tail): P156
Inverse relation (tail \u2192 head): P155