Perhaps you should try some spelling variations:
berkeley unix » berkeley usa
unix lectures » union lectures, munich lectures, index lectures
berkeley six » berkeley son, berkeley xi, berkeley seti
six lectures » _ lectures, six letters

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( berkeley unix lectures ) OR ( berkeley six lectures )).
• Adding a wildcard symbol may retrieve word variants: (( berkeley unix lectures ) or ( berkeley six lectures ))*.