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  1.  62
    Decidability and Computability of Certain Torsion-Free Abelian Groups.Rodney G. Downey, Sergei S. Goncharov, Asher M. Kach, Julia F. Knight, Oleg V. Kudinov, Alexander G. Melnikov & Daniel Turetsky - 2010 - Notre Dame Journal of Formal Logic 51 (1):85-96.
    We study completely decomposable torsion-free abelian groups of the form $\mathcal{G}_S := \oplus_{n \in S} \mathbb{Q}_{p_n}$ for sets $S \subseteq \omega$. We show that $\mathcal{G}_S$has a decidable copy if and only if S is $\Sigma^0_2$and has a computable copy if and only if S is $\Sigma^0_3$.
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  2.  14
    with Student Day on December 14, 2011.Sergei S. Goncharov, Byunghan Kim & Greg Restall - 2013 - Bulletin of Symbolic Logic 19 (2).
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  3.  90
    Simple and immune relations on countable structures.Sergei S. Goncharov, Valentina S. Harizanov, Julia F. Knight & Charles F. D. McCoy - 2003 - Archive for Mathematical Logic 42 (3):279-291.
    Let ???? be a computable structure and let R be a new relation on its domain. We establish a necessary and sufficient condition for the existence of a copy ℬ of ???? in which the image of R (¬R, resp.) is simple (immune, resp.) relative to ℬ. We also establish, under certain effectiveness conditions on ???? and R, a necessary and sufficient condition for the existence of a computable copy ℬ of ???? in which the image of R (¬R, resp.) (...)
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  4.  15
    Participants and titles of lectures.Klaus Ambos-Spies, Marat Arslanov, Douglas Cenzer, Peter Cholak, Chi Tat Chong, Decheng Ding, Rod Downey, Peter A. Fejer, Sergei S. Goncharov & Edward R. Griffor - 1998 - Annals of Pure and Applied Logic 94 (1):3-6.
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  5. Mathematical Problems from Applied Logic I.Dov M. Gabbay, Sergei S. Goncharov & Michael Zakharyaschev - 2007 - Studia Logica 87 (2-3):363-367.
     
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