1
Έκδοση 1969
Full text available from ABI/INFORM Global: 01/01/1999 to present
Full text available from Continental Europe Database: 01/01/1999 to present
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
2
Full text available from ABI/INFORM Global: 01/01/2017 to present
Full text available from East Europe, Central Europe Database: 01/01/2017 to present
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
3
Full text available from ABI/INFORM Global: 03/01/2004 to present
Full text available from Canadian Business & Current Affairs Database: 03/01/2004 to present
Full text available from Healthcare Administration Database: 03/01/2004 to present
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
4
Έκδοση 2008
Full text available from ABI/INFORM Global: 08/01/2005 to present
Full text available from Latin America & Iberia Database: 08/01/2005 to present
Full text available from Research Library: 08/01/2005 to present
Ηλεκτρονική πηγή Επιστημονικό περιοδικό
5
Έκδοση 1979
Full text available from ABI/INFORM Global: 01/01/2004 to present
Full text available from Latin America & Iberia Database: 01/01/2004 to present
Ηλεκτρονική πηγή Επιστημονικό περιοδικό