See the North Dakota Naturalization Records Index at
http://www.lib.ndsu.nodak.edu/database/naturalrec.html There are two listings (likely for the same person):
Danrot, Nils M Sweden March 03, 1905
1st(Papers) Burleigh(County) D-4(Volume) 215(Page)
Danrot, Nils Magnus Sweden May 16, 1911
2nd(Papers) Burleigh(County) P-15(Volume) 114(Page)
There were two steps to the Naturalization procedure--the 'Declaration of Intention' and the 'Naturalization Records'--therefore, the two Papers mentioned above. There is further information concerning the history of these records, on this site. You can order copies of naturalization records for all North Dakota counties through this link: mailto:archives@pioneer.state.nd.us