About the Authors

Judyta J. Gładykowska-Rzeczycka

Affiliation Professor retired, Marusarzówny, Gdańsk, Poland

Dariusz Nowakowski

darekn@hot.pl

Affiliation Department of Anthropology, Wrocław University of Environmental and Life Sciences, Kożuchowska, Wrocław, Poland

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JJGR DN. Performed the experiments: DN. Analyzed the data: DN. Contributed reagents/materials/analysis tools: JJGR DN. Wrote the paper: DN.