Scope and Contents: Manuscripts for addresses, lectures and articles, a few by other authors. Danish Biographical Encyclopedia manuscripts. Oppositions to dissertations. Reprints of articles by Pihl and by others. Pihl bibliography. 1 box with Neugebauer reprints. 1 box with private correspondence.
Correspondents include: Aage Bertelsen, Harald Bohr, Max Born, K.M. Carstens, J.A. Christiansen, S.J. Dyksterhuis, Louis Hjelmslev, Egil Hylleraas, Sigurd Højby, E.S. Johansen, Jørgen Jørgensen, Hendrik Anton Kramers, Kirstine Meyer, Otto Neugebauer, H. Oppermann, Poul Rubinstein, Harald Wergeland.