Perhaps you should try some spelling variations:
"doi ca chap snippets" » "doi ca code snippets", "doi cau chap snippets", "doi ca cham snippets", "doi ca chep snippets", "doi cua chap snippets", "doi cay chap snippets", "duoi ca chap snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data snippets"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("python using java snippets") or ("doi ca chap snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java snippets") OR ("doi ca chap snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( python using java snippets ) or ( doi ca chap snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("python using java snippets") or ("doi ca chap snippets"))) or ("locating bug core snippets"))*.