Chemical bond in ferroeletric perovskies / Katarzyna TKACZ-ŚMIECH, A. KOLEŻYŃSKI, W. S. PTAK // Ferroelectrics ; ISSN 0015-0193. — 2000 vol. 237 iss. 1, s. 57–64. — Bibliogr. s. 64. — Publikacja dostępna online od: 2011-10-26. — 9th European Meeting on Ferroelectricity (EMF-9) : Prague, Czech Republic, 12–16 July 1999. — tekst: https://www-1tandfonline-1com-15qtywsqb0146.wbg2.bg.agh.edu.pl/doi/pdf/10.1080/00150190008216232

Irreversible temperature effects in infrared spectra of amorphous C, N, H – containing layers / I. HOŁYST, S. JONAS, C. PALUSZKIEWICZ, W. S. PTAK // W: Vibrational Spectroscopy in Materials Science : III International Conference : 23–26 September 2000 Kraków – Poland : book of abstracts / organized by University of Mining and Metallurgy. Department of Materials Science and Ceramics, Jagiellonian University. Regional Laboratory of Physicochemical Analyses and Structural Research. — Kraków : Wydawnictwo Naukowe „Akapit”, 2000. — ISBN10: 83-7108-70-0. — S. 76

Pauling's electrostatic rule for partially covalent/partially ionic crystals / K. TKACZ-ŚMIECH, A. KOLEŻYŃSKI, W. S. PTAK // Journal of Physics and Chemistry of Solids ; ISSN 0022-3697. — 2000 vol. 61 iss. 11, s. 1847–1853. — Bibliogr. s. 1853, Abstr.. — Publikacja dostępna online od: 2000-08-30. — tekst: https://www-1sciencedirect-1com-10000276k0252.wbg2.bg.agh.edu.pl/science/article/pii/S0022369700000664/pdfft?md5=547df9a024c86f43c725d3b77b5623ce&pid=1-s2.0-S0022369700000664-main.pdf

Properties of the B-O bond in the nonlinear optical materials / U. MORYC, W. S. PTAK // W: Vibrational Spectroscopy in Materials Science : III International Conference : 23–26 September 2000 Kraków – Poland : book of abstracts / organized by University of Mining and Metallurgy. Department of Materials Science and Ceramics, Jagiellonian University. Regional Laboratory of Physicochemical Analyses and Structural Research. — Kraków : Wydawnictwo Naukowe „Akapit”, 2000. — ISBN10: 83-7108-70-0. — S. 94