who coached the 1974 purdue boilermakers football team and then again in 1976 purdue boilermakers football team ?
SELECT DISTINCT var_uri where brack_open dbr_1974_Purdue_Boilermakers_football_team dbo_coach var_uri sep_dot dbr_1976_Purdue_Boilermakers_football_team dbo_coach var_uri brack_close