Voitenkov, V B
Klimkin, A V
Skripchenko, N V
Pulman, N F
Ivanova, M V
Article History
Received: 27 March 2015
Revised: 21 May 2015
Accepted: 27 June 2015
First Online: 4 August 2015
Competing interests
: The authors declare no conflict of interest.