Zgłoś błąd związany z obiektem: Acid-base equilibrium of 3-R1-4-R-thiazol-2-one hydrazonederivatives. 5. Ionization constants of a-methyl-ß-(3,4-dimethylthiazol-2-ylidene)-hydrazides of picolinic, nicotinic and isonicotinic acids