Media type: E-Article Title: Improved approximability and non-approximability results for graph diameter decreasing problems Contributor: Bilò, Davide; Gualà, Luciano; Proietti, Guido imprint: Elsevier BV, 2012 Published in: Theoretical Computer Science Language: English DOI: 10.1016/j.tcs.2011.05.014 ISSN: 0304-3975 Origination: Footnote: Access State: Open Access