Heuristic proofs E. A. Hirsch General Mathematics Seminar of the St. Petersburg Division of Steklov Institute of Mathematics, Russian Academy of Sciences December 26, 2011 13:00
Semialgebraic proofs E. Hirsch General Mathematics Seminar of the St. Petersburg Division of Steklov Institute of Mathematics, Russian Academy of Sciences March 25, 2003
Semialgebraic proofs E. A. Hirsch Meetings of the St. Petersburg Mathematical Society March 25, 2003
“Non-logical” proofs of logical formulas E. A. Hirsch General Mathematics Seminar of the St. Petersburg Division of Steklov Institute of Mathematics, Russian Academy of Sciences November 20, 2000