Perhaps you should try some spelling variations:
reference methods » preference methods, inference methods, difference methods
reference method » difference method, difference methods
programmers code » programmers guide, programmer's case, programming code
code microscopy » mode microscopy, ore microscopy, modern microscopy
https » http

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((reference methods) OR (reference method)) programmers code microscopy https~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((reference methods) OR (reference method)) programmers code microscopy https".
• Adding a wildcard symbol may retrieve word variants: ((reference methods) OR (reference method)) programmers code microscopy https*.