Danish linguist and runologist (1839–1920)
Decoration of the Cross of Honour of the Dannebrog
Grand Cross of the Order of the Dannebrog
honorary doctor of the Leipzig University
honorary doctorate of the University of Oslo
Royal Society of Arts and Sciences in Gothenburg
Royal Danish Academy of Sciences and Letters
Göttingen Academy of Sciences and Humanities in Lower Saxony
Brockhaus and Efron Encyclopedic Dictionary
Meyers Konversations-Lexikon, 4th edition (1885–1890)