Perhaps you should try some spelling variations:
mental survey » general survey (Expand Search), medical survey (Expand Search), postal survey (Expand Search)
center serve » center servers (Expand Search), center service (Expand Search), center survey (Expand Search)
benign nevus » benign nevi (Expand Search), benign neck (Expand Search), benign nerve (Expand Search)
survey app » survey aps (Expand Search), survey a (Expand Search), survey april (Expand Search)
j center » j centner (Expand Search), j centeno (Expand Search), j cestero (Expand Search)
j mental » j mengual (Expand Search), j mena (Expand Search), j mehta (Expand Search)
j benign » j benigno (Expand Search), _ benign (Expand Search), a benign (Expand Search)
serve a » serve _ (Expand Search), reserve a (Expand Search)
app de » rapp de (Expand Search), app do (Expand Search), trapp de (Expand Search)
case 2 » case _ (Expand Search), case 1 (Expand Search)

You can also try:

• Europeana
• Digital Public Library of America
• CORE

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: (( j center serve a del ) OR ((( j mental survey app de ) OR ( j benign nevus case 2 ))))~.
• Adding a wildcard symbol may retrieve word variants: (( j center serve a del ) or ((( j mental survey app de ) or ( j benign nevus case 2 ))))*.