R. Freund, A. Alhazov, S. Ivanov:
"Introducing the Concept of Activation and Blocking of Rules in the General Framework for Regulated Rewriting in Sequential Grammars.";
in: "Sixteenth Brainstorming Week on Membrane Computing", Gh. Paun et al. (ed.); Fénix Editora, Sevilla, 2018, 1 - 22.
https://publik.tuwien.ac.at/files/publik_276092.pdf