After obtaining a Specialist's or Master's Degree, a student may enter a university or a scientific institute to pursue postgraduate education. The first level of postgraduate education is aspirantura that usually results in the Candidate of Sciences degree. The seeker should pass three exams (in his/her special field, in a foreign language of his/her choice, and in history and philosophy of science), publish at least three scientific articles in peer-reviewed journals, write a dissertation and defend it. This degree is roughly equivalent to the Ph.D. in the United States. After graduation a student may continue postgraduate education. After several (2 to 4) years of study in doctorantura, if they obtain important scientific results, publish them and write another thesis, the Doctor of Sciences degree can be awarded. Typically, the post-graduate works in the university or scientific institute while preparing their new thesis. The average time between obtaining Candidate and Doctor degrees is roughly 10 years, and most of new Doctors are 40 and more
years old. Only 1 in 4 Candidates reaches this grade. Granting of advanced degrees is overseen by the Higher Attestation Commission of the Ministry of Education and
Science.