(2017/09/19) Many sites are reporting inconsistent and confusing search results in Worldcat Discovery. One site reported this response from the vendor:
"OCLC is working to add server capacity and hope to have it completed in about a month. The OCLC systems folks are working throughout the day to mitigate some of the problems, but it was indicated to me that 10am to 2pm EST are peak times and will be problematic. The problems will impact both Discovery and WMS"
We have experienced inexplicable results, non-working request buttons, etc. Repeating your search may give different results, but we suggest you use the library catalog for now. We will keep you posted on the status.