Registry re3data.org

Principles of searching in registers differ from those used in article databases.

First of all, start searching a broader area that fits your research topic: physics, bioinformatics, art, political sciences etc. Results can be limited by using different filters.

Let's take political sciences as an example:

As a result we have 81 repositories on political sciences

Pictographs in the upper right corner characterise the repository: 

We can choose content type raw data from limiters, there should be 23 repositories. 

Klicking on  Data Sharing for Demographic Research we can find more precise description of the repository and we are directed to its location: http://www.icpsr.umich.edu/icpsrweb/DSDR/

Example: Search about Estonia or Estonians inside this repository

http://www.icpsr.umich.edu/icpsrweb/DSDR/studies/3485?archive=DSDR&q=estonia*

results with the fact that 142 persons immigrated from Estonia to USA in 1999. 

Datasets can be downloaded via Quick Download or Download all files, in this case for members of ICPSR only.