Perhaps you should try some spelling variations:
"interna cells" » "internal cells", "internodal cells", "internal shells"
"internal cell" » "internal cells", "maternal cell", "internodal cells"
"stern cells" » "stem cells", "stems cells", "pattern cells", "steroid cells"
"stern cell" » "steroid cell", "pattern cell"

Try widening your search to All Fields.

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: (((("stern cells") OR ((("interna cells") OR ("internal cell"))))) OR ("stern cell")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"stern cells\") or (((\"interna cells\") OR (\"internal cell\"))))) or (\"stern cell\"))".
• Removing quotes may allow a broader search: (((( stern cells ) or ((( interna cells ) OR ( internal cell ))))) or ( stern cell )).
• Adding a wildcard symbol may retrieve word variants: (((("stern cells") or ((("interna cells") OR ("internal cell"))))) or ("stern cell"))*.