Chapter 1. Life and career of Tatjana Afanassjewa (Margriet van der Heijden).- Chapter 2. Geometry and pedagogy of mathematics (Marianna Antonutti Marfori).- Chapter 3. Afanassjewa's work on thermodynamics (Jos Uffink).- Chapter 4. The Ehrenfests on statistical mechanics I: Irreversibility (Roman Frigg).- Chapter 5. The Ehrenfests on statistical mechanics II: Phase average and time average (Patricia Palacios).- Chapter 6. The Ehrenfests' use of toy models (Josh Luczak, University of Hannover (Lena Zuchowski).- Chapter 7. Tatjana Afanassjewa and the Principle of Similitude (Jos Uffink).- Chapter 8. Translation from German: Foundations of Thermodynamics 1925 and 1956 (Marina Baldissera Pacchetti).- Chapter 9. Translation from Dutch: papers on the pedagogy of mathematics (Pauline van Wriest).