Perhaps you should try some spelling variations:
"the urban skills survey" » "the urban hills survey", "the german skills survey", "the green skills survey"
"the urban bias series" » "the urban stias series", "the urban bias sources", "the urban atlas series", "the urban bus series"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"the urban bias series\") OR (\"the urban skills survey\"))".
• Removing quotes may allow a broader search: (( the urban bias series ) OR ( the urban skills survey )).
• Adding a wildcard symbol may retrieve word variants: (("the urban bias series") OR ("the urban skills survey"))*.