killing of four policemen in an ambush in Rentería
... that the killing of four policemen in an ambush in Rentería was the Basque separatist group ETA's deadliest attack of 1982?
... that the <b id="mwDUo"><a href="./September_1982_Rentería_attack" id="mwDUs" rel="mw:WikiLink" title="September 1982 Rentería attack">killing of four policemen in an ambush in Rentería</a></b> was the Basque separatist group <a href="./ETA_(separatist_group)" id="mwDUw" rel="mw:WikiLink" title="ETA (separatist group)">ETA</a>'s deadliest attack of 1982?