http://onlinelibrary.wiley.com/doi/10.1111/j.1745-4530.2010.00594.x/full
http://onlinelibrary.wiley.com/doi/10.1111/jfpe.12045/full
http://onlinelibrary.wiley.com/doi/10.1111/j.1745-4530.2007.00226.x/full
http://onlinelibrary.wiley.com/doi/10.1111/jfpe.12066/full
با سلام و خسته نباشید.