Blanco, J.M. 2021. EF4, EF4-M and EF4-Ł: A companion to BN4 and two modal four-valued systems without strong Łukasiewicz-type modal paradoxes. Logic and Logical Philosophy. 31, 1 (Aug. 2021), 75–104. DOI:https://doi.org/10.12775/LLP.2021.010.