Stepan L. Kuznetsov, “Complexity of the Lambek calculus and its extensions”, Stud. Comput. Intell., 1081 (2023), 1–29
Tikhon Pshenitsyn, “From Double Pushout Grammars to Hypergraph Lambek Grammars With and Without Exponential Modality”, Electron. Proc. Theor. Comput. Sci., 377 (2023), 9
Stepan Lvovich Kuznetsov, Matematicheskie osnovy informatiki i informatsionno-kommunikatsionnykh sistem, 2021, 176