Riksmål became the chosen language for Norwegian pupils from the latter part of the 19th century, and Norwegian newspapers adapted to the language. However, many Norwegian authors, such as Henrik Ibsen, Bjørnstjerne Bjørnson and Knut Hamsun, did not adhere and continued using Danish. Riksmål got an official writing norm in 1907, and in 1917 a new reform introduced some elements from Norwegian dialects and Nynorsk as optional alternatives to traditional Dano-Norwegian forms.