Perhaps you should try some spelling variations:
surface expression » surface erosion
information root » information robots, information role, information report
root surface » flat surface
array string » array strong, arrays strings, array sharing
array fermi » array forming, array format
array using » arrays using

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: information root surface expression ((array string) OR (((array fermi) OR (array using))))~.
• Adding a wildcard symbol may retrieve word variants: information root surface expression ((array string) or (((array fermi) or (array using))))*.