The proceedings of the Conferences "IQSA Quantum Structures Nijmegen 2017" and "Quantum Structures Kazan 2018" will be jointly published in a special issue of International Journal of Theoretical Physics, published by Springer (guest editors Airat Bikchentaev and Soroush Rafiee Rad). The submission deadline is November 1, 2018. Papers can be submitted at (please choose "S.I. : Nijmegen 2017" or "S.I. : IQSA 2018", depending on which event your contribution refers to, under article type) - feel free to contact the guest editors for any specific query on the special issue.