| Name | Info | Provider | Link |
|---|---|---|---|
| subscription/membership/fee required | Ingenta plc | https://www.ingentaconnect.com/openurl?genre=article&issn=&volume=4&issue=2&spage=94&aulast=Harfouche | |
| subscription/membership/fee required | Ovid Technologies, Inc. | http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=20470242.ui | |
| subscription/membership/fee required | Bentham Science Publishers Ltd. | http://www.eurekaselect.com/94150/article |