Murali Krishna Medudula, Mahim Sagar, Ravi Parkash Gandhi: Telecom Management in Emerging Economies: Evolutionary and Contemporary Perspectives. India: Springer, 2016, s. 24. ISBN 978-81-322-2749-6. OCLC948285739. (ang.).
Anastasija Bogatikowa: The Mobile Telecommunications Market. W: Investing in St Petersburg. Marat Tiertierow (red.). London: GMB Publishing Ltd, 2005, s. 264. ISBN 978-1-905050-73-4. OCLC62892845. (ang.).
