sentences:  In 1921 he was with the Danish Ambulance service in Poland during the Polish–Soviet War.In 1922 he returned to Russia as leader of the Danish Red Cross delegation in Fridtjof Nansen's efforts to alleviate the Russian Famine of 1921-22.In 1922 Carl Krebs organized and led an expedition to establish a farming, mining and fur trading settlement near Erdenebulgan in the Khövsgöl province of northern Mongolia, however the enterprise never prospered.