Which coach of the Chicago Bulls during the year 1981 won the NBA Coach of the Year award in the 1970s?
"Chicago Bull" is the name of team; during the year 1981 refers to year = 1981; 'NBA Coach of the Year' is the award; in the 1970s refers to year between 1970 to 1979
SELECT DISTINCT T2.coachID FROM coaches AS T1 INNER JOIN awards_coaches AS T2 ON T1.coachID = T2.coachID INNER JOIN teams AS T3 ON T3.tmID = T1.tmID WHERE T2.award = 'NBA Coach of the Year' AND T2.year BETWEEN 1970 AND 1979 AND T1.year = 1981 AND T3.name = 'Chicago Bulls'