2-Naphthalenecarboxylic acid, 3-hydroxy-4-((2-sulfo-1-naphthalenyl)azo)-, strontium salt (1:1) 3-Hydroxy-4-((2-sulfo-1-naphthalenyl)azo)-2-naphthalenecarboxylic acid, strontium salt (1:1) 73612-33-6