Perhaps you should try some spelling variations:
reference python » reference method, reference author, reference edition
microscope https » microscopy https, microscope its, microscope study
python programs » python program, action programs, method programs
microscope hans » microscope nano, microscope a, microscope images
programs based » programs case, programming based

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "reference python programs based ((microscope https) OR (microscope hans))~".
• Adding a wildcard symbol may retrieve word variants: reference python programs based ((microscope https) OR (microscope hans))*.