^Bratberg, Terje; Mardal, Magnus A.
"Oscar 2.". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 4 January 2024.
^Hoel, Oddmund Løkensgard.
"Olav Hoprekstad". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 9 January 2024.
^Bratberg, Terje; Mardal, Magnus A.
"Oscar 2.". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 4 January 2024.
^Hoel, Oddmund Løkensgard.
"Olav Hoprekstad". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 9 January 2024.