Perhaps you should try some spelling variations:
"graph ramsey john ray" » "graphs ramsey john ray", "frank ramsey john ray", "graph ramsay john ray", "graph casey john ray", "graph bradley john ray", "graph ramsey john r"
"raja r mon roy" » "raja r von roy", "raja r mohon roy", "raja r kwon roy", "raja j mon roy", "raja m mon roy", "raja a mon roy", "raja o mon roy", "raja r mod roy"
"raja _ mon roy" » "raja _ von roy", "raja _ mohon roy", "raja _ kwon roy"

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: (("graph ramsey john ray") OR ((("raja r mon roy") OR ("raja _ mon roy")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"graph ramsey john ray\") or (((\"raja r mon roy\") OR (\"raja _ mon roy\"))))".
• Removing quotes may allow a broader search: (( graph ramsey john ray ) or ((( raja r mon roy ) OR ( raja _ mon roy )))).
• Adding a wildcard symbol may retrieve word variants: (("graph ramsey john ray") or ((("raja r mon roy") OR ("raja _ mon roy"))))*.