Analysis of information sources in references of the Wikipedia article "بيل كوش (متزحلق نوردي مزدوج)" in Arabic language version.
America's Bill Koch first observed the skate step at a Swedish marathon, then applied it to win the 1982 World Cup of Cross Country skiing.
America's Bill Koch first observed the skate step at a Swedish marathon, then applied it to win the 1982 World Cup of Cross Country skiing.