Perhaps you should try some spelling variations:
"electronic microscope" » "electron microscopes", "electron miscroscope", "electron microscopic"
"electronic microscopy" » "electronic spectroscopy", "electron cryomicroscopy", "electron microscopic"
"electron microcopy" » "electron microscopic", "electron microscopes", "reflection microscopy"

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: (((("electron microscope") OR ((("electronic microscope") OR ((("electronic microscopy") OR ("electron microcopy"))))))) OR ("electron microscopy"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"electron microscope\") or (((\"electronic microscope\") or (((\"electronic microscopy\") OR (\"electron microcopy\"))))))) or (\"electron microscopy\"))*".
• Removing quotes may allow a broader search: (((( electron microscope ) or ((( electronic microscope ) or ((( electronic microscopy ) OR ( electron microcopy ))))))) or ( electron microscopy ))*.