Perhaps you should try some spelling variations:
"positive-indefinite inner" » "positive-indefinite integrals", "positive-indefinitive inner"
"positive-indefinite kernel" » "positive-indefinitive kernel"
"positive-definite kernels" » "positive-definitive kernels"

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: (((("positive-indefinite kernel") OR ("positive-definite kernels"))) OR ("positive-indefinite inner")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"positive-indefinite kernel\") OR (\"positive-definite kernels\"))) or (\"positive-indefinite inner\"))".
• Removing quotes may allow a broader search: (((( positive-indefinite kernel ) OR ( positive-definite kernels ))) or ( positive-indefinite inner )).
• Adding a wildcard symbol may retrieve word variants: (((("positive-indefinite kernel") OR ("positive-definite kernels"))) or ("positive-indefinite inner"))*.