.alpha.-Naphthol-4-sulfonic acid 1,4-Oxy Acid 1-Hydroxy-4-naphthalenesulfonic acid 1-Hydroxynaphthalene-4-sulfonic acid 1-Naphthalenesulfonic acid, 4-hydroxy- 1-Naphtho-4-sulfonic acid 1-Naphthol-4-sulfonic acid 4-Hydroxy-1-naphthalenesulfonic acid 84-87-7 NSC9587 NW Acid Nevile and Winther's acid Neville-winther acid