Perhaps you should try some spelling variations:
"reproduction planning / computer program" » "preproduction planning / computer program", "production planning / computer program", "reproductive planning / computer program"
"introduction planning / computer program" » "introduction explaining / computer program", "production planning / computer program", "introduction learning / computer program"

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: (("reproduction planning / computer program") OR ("introduction planning / computer program")).
• Removing quotes may allow a broader search: (( reproduction planning / computer program ) or ( introduction planning / computer program )).
• Adding a wildcard symbol may retrieve word variants: (("reproduction planning / computer program") or ("introduction planning / computer program"))*.