Perhaps you should try some spelling variations:
"variable start" » "variable stars", "variable state", "variable part", "variable starst"
"variable star" » "variable stars"
"variable step" » "variable stars", "variable speed", "variable scope"

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: (((("variable star") OR ("variable start"))) OR ("variable step")).
• Removing quotes may allow a broader search: (((( variable star ) or ( variable start ))) or ( variable step )).
• Adding a wildcard symbol may retrieve word variants: (((("variable star") or ("variable start"))) or ("variable step"))*.