“Tautomeric forms study of 1H-(2′-pyridyl)-3-methyl-5-hydroxypyrazole and 1H-(2′-pyridyl)-3-phenyl-5-hydroxypyrazole. Synthesis, structure, and cytotoxic activity of their complexes with palladium(II) ions” Michal Ciolkowski, Piotr Paneth, Ingo-Peter Lorenz, Peter Mayer, Marek Rozalski, Urszula Krajewska, Elzbieta Budzisz, J. Enz. Inhib. Med. Chem. 24, 1257-1268 (2009)