Dean Crnkovic Maarten De Boeck Francesco Pavese Andrea Svob q-Analogs of divisible design graphs and Deza graphs. 106047 2025 215 J. Comb. Theory, Ser. A https://doi.org/10.1016/j.jcta.2025.106047 db/journals/jcta/jcta215.html#CrnkovicBPS25 streams/journals/jcta