In January 1926 Schreier attended a lecture given by Reidemeister in Hamburg on finding presentations for normal subgroups of finitely presented groups. Reidemeister published his method later in 1926. Schreier, who took a more algebraic approach compared to Reidemeister 's geometrical approach, was able to extend Reidemeister 's method to arbitrary subgroups and, by cleverly choosing generators for the subgroup, was able to greatly simplify the presentation obtained.
Sa Enero 1926 Schreier pumasok sa isang panayam na ibinigay ng Reidemeister sa Hamburg sa paghanap ng mga presentasyon para sa normal na subgroups ng finitely ipinapahayag grupo. Reidemeister-publish ang kanyang paraan mamaya sa 1926.