Perhaps you should try some spelling variations:
"graph ramsey john roe" » "graphs ramsey john roe", "frank ramsey john roe", "graph ramsay john roe", "graph casey john roe", "graph ramsey john rose", "graph ramsey john rowe", "graph ramsey john rolle"
"raja m mohon roy" » "raja m cohen roy", "raja m mon roy", "raja m moxon roy", "raja m morton roy", "raja _ mohonk roy", "raja _ mohon roy", "raja j mohon roy", "raja r mohon roy"
"raja m mohan roy" » "raja m mohan r", "raja m mohan rai", "raja m roman roy", "raja _ mohan roy", "raja r mohan roy", "raja b mohan roy", "raja j mohan 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 roe") OR ((("raja m mohon roy") OR ("raja m mohan roy")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"graph ramsey john roe\") or (((\"raja m mohon roy\") OR (\"raja m mohan roy\"))))".
• Removing quotes may allow a broader search: (( graph ramsey john roe ) or ((( raja m mohon roy ) OR ( raja m mohan roy )))).
• Adding a wildcard symbol may retrieve word variants: (("graph ramsey john roe") or ((("raja m mohon roy") OR ("raja m mohan roy"))))*.