UL 1433-2003 UL Standard for Safety Control Centers for Changing Message Type Electric Signs (Fourth Edition; Reprint with Revisions Through and Including May 18@ 2006)
2011UL 1433 BULLETIN-2011 UL Standard for Safety Control Centers for Changing Message Type Electric Signs
2003UL 1433-2003 UL Standard for Safety Control Centers for Changing Message Type Electric Signs (Fourth Edition; Reprint with Revisions Through and Including May 18@ 2006)
1996UL 1433-1996 UL Standard for Safety Control Centers for Changing Message Type Electric Signs (Third Edition; Reprint with Revisions Through and Including July 06@ 1998)
1991UL 1433-1991 UL Standard for Safety Control Centers for Changing Message Type Electric Signs (Second Edition; Reprint with Revisions Through and Including March 11@ 1992)