Perhaps you should try some spelling variations:
"selected supplementary materials" » "selected supplementary material", "required supplementary materials"
"levant supplementary services" » "levant supplementary exercises", "eleven supplementary services", "level supplementary services", "cleaner supplementary services"

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: "((\"levant supplementary services\") OR (\"selected supplementary materials\"))".
• Removing quotes may allow a broader search: (( levant supplementary services ) OR ( selected supplementary materials )).
• Adding a wildcard symbol may retrieve word variants: (("levant supplementary services") OR ("selected supplementary materials"))*.