1
Full text available from European Newsstream: 07/15/2013 to 10/31/2016
Full text available from Global Breaking Newswires: 07/15/2013 to 10/31/2016
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
2
Full text available from European Newsstream: 07/31/2013 to 09/30/2016
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
3
Full text available from European Newsstream: 07/18/2013 to 10/27/2016
Ηλεκτρονική πηγή Εφημερίδα
4
Έκδοση 1998
Full text available from Earth, Atmospheric & Aquatic Science Database: 01/01/2012 to present
Full text available from East Europe, Central Europe Database: 01/01/2012 to present
Full text available from Research Library: 01/01/2012 to present
Ηλεκτρονική πηγή Περιοδική έκδοση