Oleg Verbitsky 0001 Maksim Zhukovskii The Descriptive Complexity of Subgraph Isomorphism Without Numerics. 308-322 2017 CSR https://doi.org/10.1007/978-3-319-58747-9_27 conf/csr/2017 db/conf/csr/csr2017.html#VerbitskyZ17