1-Naphthol-3,6-disulfonic acid, 8-amino-2-[[p-[[p-[(p-hydroxyphenyl)azo]phenyl]thio]phenyl]azo]-7-[(p-nitrophenyl)azo]-, compd. with guanidine, 1,3-di-o-tolyl- 2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-6-[[p-[[p-[(p-hydroxyphenyl)azo]phenyl]thio]phenyl]azo]-3-[[p-nitrophenyl]azo]-, compd. with guanidine,1,3-di-o-tolyl- NSC80902