Perhaps you should try some spelling variations:
"open resources software" » "open source software", "open outsourced software", "open measures software", "ocean resources software", "open sources software", "own resources software", "open sourcess software"
"open resource software" » "open source software", "open opensource software", "open resonance software", "ocean resource software", "open sources software"
"human resource software" » "human source software", "human opensource software", "human resonance software"

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: (((("open resource software") OR ("open resources software"))) OR ("human resource software")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"open resource software\") OR (\"open resources software\"))) or (\"human resource software\"))".
• Removing quotes may allow a broader search: (((( open resource software ) OR ( open resources software ))) or ( human resource software )).
• Adding a wildcard symbol may retrieve word variants: (((("open resource software") OR ("open resources software"))) or ("human resource software"))*.