" Metro 2034 " , an indirect sequel to " Metro 2033 " , has sold some 300,000 copies in just 6 months , making it Russia 's biggest local bestseller in 2009 .
Head entity: metro 2034 Q1365904 1 2
Tail entity: metro 2033 Q916423 10 11
Relation (head \u2192 tail): P155
Inverse relation (tail \u2192 head): P156