Rudiger Gobel: An Appreciation (Droste, Fuchs, Goldsmith, Strungman).- Part I: Survey Articles.- Properties of Abelian groups determined by their endomorphism ring (Albrecht).- The zero-divisor graph of a commutative semigroup: a survey (Anderson, Badawi).- A Remak-Krull-Schmidt class of torsion-free Abelian groups (Arnold, Mader, Mutzbauer, Solak).- Rigid À1-free Abelian groups with prescribed factors and their role in the theory of cellular covers (Strungmann).- Definable valuations induced by definable subgroups (Dupont).- Groups of automorphisms of totally ordered sets: techniques, model theory and applications in decision problems (Glass).- Algebraic entropies for Abelian groups with applications to the structure of their endomorphism rings: a survey (Goldsmith, Salce).- On subsets and subgroups defined by commutators and some related questions (Charlotte Kappe, Longobardi, Maj).- Recent progress in module approximations (Trlifaj).- Part II: Research Articles.- A class of pure subgroups of the Specker group (Corner).- Countable 1-transitive trees (Chicot, Truss).- On Ore's theorem and universal words for permutations and injections of infinite sets (Droste).- An extension of M.C.R. Butler's theorem on endomorphism rings (Dugas, Herden, Shelah).- The Jacobson radical's role in isomorphism theorems for p-adic modules extends to topological isomorphism (Flagg).- A note on Hieronymi's theorem: every definably complete structure is definably Baire (Fornasiero).- Cotorsion and Tor pairs and finitistic dimensions over commutative rings (Fuchs).- Permutation groups without irreducible elements (Glass, Macpherson).- R-Hopfian and L-co-Hopfian Abelian groups (with an appendix by A.L.S. Corner on near automorphisms of an Abelian group) (Goldsmith, Gong).- On the Abelianization of certain topologist's products (Herfort, Hojka).- Some remarks on DP-minimal groups (Kaplan, Levi, Simon).- Square subgroups of decomposable rank three groups (Karimi).- An invariant on primary Abelian groups with applications to their projective dimensions (Keef).- The valuation difference rank of a quasi-ordered difference field (Kuhlmann, Matusinski, Point).- The lattice of U-sequences of an Abelian p-group (McLean).- Strongly non-singular rings and Morita equivalence (McQuaig).- The class of (2,3)-groups with homocyclic regulator quotient of exponent p2 (Solak).- Unbounded monotone subgroups of the Baer-Specker group (Wald).- Clusterization of correlation functions (Zuevsky).