• Department of Structural DesignLaul, Heinrich; Otsmaa, Vello; Aare, Johannes; Kulbach, Valdek; Õiger, Karl; Soonurm, Enno; Jaaniso, Valdo; Jürgenson, Leo; Pihlak, IlmarResearch activities / Tallinn Technical University1993 / p. 60-62 https://www.ester.ee/record=b1053754*est