Irina Perfilieva, Michael Wagenknecht: Editorial -- Maria Ždímalová, Lubica Staneková: Asymptotic Comparison of Two Constructions for Large Digraphs of Given Degree and Diameter -- Radka Malíková: On a Generalization of Helmholtz Conditions -- Jitka Kühnová: Analysis of the Predator-Prey Model with Climax Prey Population í -- Martin Sleziak, Miloš Ziman: Range of Density Measures -- Chawalit Boonpok: d-Closed Sets in Biclosure Spaces -- Larry Ericksen: Prime Constellations in Triangles with Binomial Coefficient Congruences -- Anne-Maria Ernvall-Hytonen, Art o Lepistö: Bounds and Computational Results for Exponential Sums Related to Cusp Forms