1. Professor Per Ekwall 1895–1990
2. Harva, O. 1951. “The properties of tall oil rosin soap and its mixtures with fatty acid soaps in aqueous solutions”. Åbo, Turku: Åbo Akademi University. Thesis
3. Bruun, H. 1954. “Surface balance studies of rosin acid monolayers”. Turku: Åbo Akademi University, Åbo. Thesis