[1]
Ellingsen, E. and Mac Donald, K. 2010. Norsk på 1-2-3. Cappelen Damm.
[2]
Mac Donald, K. and MacDonald, M. 2013. Exploring Norwegian grammar. Cappelen Damm.
[3]
Strandskogen, A.-B. et al. 1986. Practical Norwegian grammar. Oris.
[4]
Strandskogen, Åse-Berit and Strandskogen, Rolf 1995. Norwegian: an essential grammar. Routledge.