The wetcanvas Search facility has its limitations, it will not accept three letter words in search criteria such as "Pen and Wash" or WIP etc. It is also quite slow.
I recommend you try Google Advanced Search
and put the searched for phrase in the "this exact wording or exact phrase" box. Use "wetcanvas.com" in the "search with this site or domain" box:
You will find this method is very fast and thorough.