Phason and phonon contributions to the diffraction pattern of ($\sqrt{3} \times \sqrt{3}$)-type hexagonal layers / Janusz WOLNY, Stanisław KAPRAL, Lucjan PYTLIK // Philosophical Magazine. A, Physics of Condensed Matter : structure, defects and mechanical properties ; ISSN 1354-0793. — 2001 vol. 81 no. 2, s. 301–310. — Bibliogr. s. 310, Abstr.

Symmetry analysis in description of local tensor properties of crystals / W. SIKORA, L. PYTLIK, F. BIAŁAS // W: ECM 20 : 20\textsuperscript{th} European crystallographic meeting : Crystallography in natural sciences and technology : Kraków, August 25–31 2001 : book of abstracts / eds. K. Stadnicka, W. Nitek. — [Kraków : EJB Publisher], [2001]. — Opis częśc. wg okł.. — ISBN10: 8388519166. — S. 174

Symmetry analysis in description of local tensor properties of crystals / W. SIKORA, L. PYTLIK, F. BIAŁAS // W: Symmetry and structural properties of condensed matter : sixth's International School on Theoretical Physics : Myczkowce, Poland, 31 August–6 September 2000 : [proceedings] / eds. T. Lulek, B. Lulek, A. Wal. — Singapore [etc.] : World Scientific, 2001. — S. 116–121. — Bibliogr. s. 121

Uniqueness of solutions in the symmetry analysis of incommensurate magnetic structures / Wiesława SIKORA, Lucjan PYTLIK, Franciszek BIAŁAS // W: Aperiodic structures 2001 : Krynica, 31 August–5 September / ed. by Janusz Wolny, Roman Wawszczak ; Faculty of Physics and Nuclear Techniques University of Mining and Metallurgy. — Kraków : Akademia Górniczo-Hutnicza. Wydział Fizyki i Techniki Jądrowej, 2001. — ISBN10:  8391479536. — S. 77–79. — Bibliogr. s. 79