Miners led by Cozma rioted in Bucharest in 1990 and 1991 , bringing down the reformist government of premier Petre Roman .
<response> Miners led by <person>Cozma</person> rioted in <location>Bucharest</location> in 1990 and 1991 , bringing down the reformist government of premier <person>Petre Roman</person> . </response>