Redirect Notice
The previous page is sending you to
https://www.sciencedirect.com/science/article/pii/S0007153678801016/pdf?md5=5ce3552f359d4e66a43f0418aa051657&pid=1-s2.0-S0007153678801016-main.pdf
.
If you do not want to visit that page, you can
return to the previous page
.