Hakala, Pauli, et al. “Durability of Sandwich Structures With a Maximized Natural Raw Material Basis: Comparison of Expanded Polystyrene, Cellulose Foam and Polylactic Acid Subjected to UV-Rain Aging”. Rakenteiden Mekaniikka, vol. 56, no. 1, May 2023, pp. 24-40, https://doi.org/10.23998/rm.120756.