1. International Year of the Periodic Table of Chemical Elements (IYPT) 2019: Planning, Coordination, and Implementation, IUPAC Project 2018-005-2-020. Co-chaired by Jan Reedijk and Natalia Tarasova (https://iupac.org/project/2018-005-2-020).
2. N. Tarasova. Chem. Int. 40, 1 (2018).
3. D. Rabinovich. Chem. Int. 41, 60 (2019).
4. B. Russell. History of Western Philosophy, Simon & Schuster, Inc., NY (1972).
5. R. Boyle. The Sceptical Chymist, pp. 30, F. Cadwell, London (1661).