 He also published on his experiences with the Akeley expedition, including on ethnic groups in the region of the expedition and the new park.Early 20th-century European efforts to lobby internationally for environmental conservation laws were delayed by World War I, but Belgian biologist Jean Massart reintroduced Paul Sarasin's proposals at the International Union of Biological Sciences (IUBS) in the 1920s.Professor Michel Siedliecki promoted them in Poland and helped to get the issue onto the agenda of the IUBS meetings of 1925, 1926, 1927 and 1928.