Want to do research more efficiently? Start by reading a concise review of the research that's already been done on your topic!
Handbook of Indigenous Education
Palgrave Handbook of Race and Ethnic Inequalities in Education
The SAGE Handbook of Comparative Studies in Education by 
The SAGE Handbook of Inclusion and Diversity in Education by Use these specialized encyclopedias similarly to the way you might use Wikipedia. They're a good a place to get a basic overview of an area and to find definitions for unfamiliar jargon. Most of them will also have a bibliography that can point you to more good sources, many of which are likely to be scholarly.
Second and Foreign Language Education
The Encyclopedia of Middle Grades Education
