Perhaps you should try some spelling variations:
tutorial microarray » factorial microarray, temporal microarray
detecting activity » detecting activities, retweeting activity, detecting agility
programs tutorial » programs tutorials, problems tutorial, programming tutorial
microarray https » microarrays https, microarray chips, microscopy https

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

• Performing a fuzzy search may retrieve terms with similar spellings: detecting activity programs tutorial microarray https~.
• Adding a wildcard symbol may retrieve word variants: detecting activity programs tutorial microarray https*.