Redirect Notice
 The previous page is sending you to https://www.sciencedirect.com/science/article/pii/0020751991901643/pdf?md5=dbb0932b97ae556e9f8e013344ac81a8&pid=1-s2.0-0020751991901643-main.pdf.

 If you do not want to visit that page, you can return to the previous page.