Karel Dekimpe: http://www.kulak.be/~dekimpe/CGGT.pdf
Olga Macedonska-Nosalska: http://mat.polsl.pl/groupland.html
Vahagn H. Mikaelian: mikaelian.pdf
Ashot Minasyan: http://www.unige.ch/math/folks/minasyan/rs/engulf-talk.pdf
Volodymyr Nekrashevych: http://www.math.tamu.edu/~nekrash/talks/ssfamilies.pdf
Tim Riley: http://www.math.cornell.edu/~riley/papers/ffl/ffl.html
Mark Sapir: http://math.vanderbilt.edu/~msapir/beamer/shanks2006.pdf
Ben Steinberg: http://mathstat.carleton.ca/~bsteinbg/slides/olshanskii.pdf
Robert Young: http://www.math.uchicago.edu/~rjyoung/papers/scalerelslides.pdf