why is maleic acid a strong acid business directory

Why is maleic acid a strong acid?
Macroporous Strong Acid Cation Exchange Resin72
Strong Acid Cation Ion Exchange Resin28
Acid suppliers
Chlorogenic Acid
Gardenia Acid
Rosmarinic Acid
Propanoic Acid; Propionic Acid; Metacetonic Acid C3H6O2 CAS 79-09-468
1H,1H,2H,2H-perfluorooctanesulfonic Acid CAS No.27619-97-299
1H,1H,2H,2H-perfluorooctanesulfonic Acid Potassiumsalt87
2,4-Dichlorophenoxyacetic Acid Herbicide40
2,4-Dichlorophenoxyacetic Acid Herbicide96
2-Amino-3-fluorobenzoic Acid CAS 825-22-914
2-Amino-3-fluorobenzoic Acid CAS 825-22-987
2-Amino-4-fluorobenzoic Acid CAS 446-32-223