Perhaps you should try some spelling variations:
"candidate snps" » "candidate snp", "candidate sets", "candidate sars"
"candidate skip" » "candidate ska", "candidate snp", "candidate asking"
"candidate spp" » "candidate snp", "candida spp", "candidate set"

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: (((((("candidate spp") OR ("candidate snps"))) OR ("candidate skip"))) OR ("candida _")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"candidate spp\") OR (\"candidate snps\"))) or (\"candidate skip\"))) or (\"candida _\"))".
• Removing quotes may allow a broader search: (((((( candidate spp ) OR ( candidate snps ))) or ( candidate skip ))) or ( candida _ )).
• Adding a wildcard symbol may retrieve word variants: (((((("candidate spp") OR ("candidate snps"))) or ("candidate skip"))) or ("candida _"))*.