1. Sang-Kil Son, “Breakdown of frustrated absorption in x-ray sequential multiphoton ionization” in CFEL-DESY Theory Seminar (CFEL, DESY, Hamburg, Germany, April 1, 2020) [oral presentation].
2. Sang-Kil Son, “Theory of X-ray–matter interactions” in Ultrafast X-ray Summer School (PULSE, Stanford, California, United States, June 15-22, 2020) [lecture].