Доступные ссылки:

Harvard: Soomere, T., Eelsalu, M., Kurkin, A. A.& Rybin, A. V. 2015. Separation of the Baltic Sea water level into daily and multi-weekly components. Continental Shelf Research, vol. 103, pp. 23-32, doi: 10.1016/j.csr.2015.04.018