"1991-12-28" . "''Sonic the Hedgehog'' (8-bit video game)" . . . . . . . . . "its 1991 predecessor" . . . "Sonic the Hedgehog (8-bit video game)" . . . . . "Sonic the Hedgehog" . . . . . . . . . . . . "''Sonic the Hedgehog''" . . . . . . . . "Sonic the Hedgehog (8-bit)" . . . "8-bit version" . . . . . . . . . . "8-bit ''Sonic the Hedgehog''" . . "Sonic the Hedgehog (8-bit video game)" . . .