* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&ved=0CHsQFjAN&url=http%3A%2F%2Flup.lub.lu.se%2Frecord%2F2278521%2Ffile%2F2278522.pdf&ei=mkDEU9X6NcaqyASslIC4BA&usg=AFQjCNFO2-nHBgoctQUmFKfgsJicXyEEPA&sig2=cnYIJxbgkP-_HZpuucWCEg&bvm=bv.70810081,d.aWw&cad=rja Lund University, Almashramah M.S. thesis] p.5 -8 | * [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&ved=0CHsQFjAN&url=http%3A%2F%2Flup.lub.lu.se%2Frecord%2F2278521%2Ffile%2F2278522.pdf&ei=mkDEU9X6NcaqyASslIC4BA&usg=AFQjCNFO2-nHBgoctQUmFKfgsJicXyEEPA&sig2=cnYIJxbgkP-_HZpuucWCEg&bvm=bv.70810081,d.aWw&cad=rja Lund University, Almashramah M.S. thesis] p.5 -8 |