^Klungsmyr, Anne Berit.
"Lars Osa". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 7 February 2024.
^Sandberg, Per-Øivind.
"Olav Johan Sopp". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 7 February 2024.
^Klungsmyr, Anne Berit.
"Lars Osa". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 7 February 2024.
^Sandberg, Per-Øivind.
"Olav Johan Sopp". In Bolstad, Erik (ed.). Store norske leksikon (in Norwegian). Oslo: Norsk nettleksikon. Retrieved 7 February 2024.