Five years later he defended the PhD thesis "Critical Analysis of the Philosophy of Logical atomism" at the Lomonossov State University in Moscow where he was a doctoral student.
In the first two years he also worked on a research project on the Berlin Group of logical empiricists around Hans Reichenbach, supported by the Fritz Thyssen Foundation.
Milkov started his work on the history of analytic philosophy, hoping to find a more refined method for achieving clear and correct thinking.
[5] Next Milkov translated Wittgenstein’s Tractatus logico-philosophicus, Philosophical Investigations and Remarks on the Foundations of Mathematics into Bulgarian.
[7] In the two books, Milkov presented all the works of G. E. Moore, Russell, Wittgenstein, John Wisdom, Gilbert Ryle, J. L. Austin, P. F. Strawson and M. Dummett in a synoptic form which "maps out" the "logical geography" of their concepts and problems.