1. D. Indriksone, I. Bremere, I. Aleksejeva, M. Gratz, S. Oisalu, J. Svirskaite, Using ecological construction materials in the Baltic States, reccomendations on using ecomaterials, Baltic Environmental Forum, Latvia (2011) p.4.
2. L. Popovs, Būvmateriāli un būvizstrādājumi, [Building materials and building-products], Riga: Zvaigzne (1978) 364.
3. Kurshs V., Stinkule A. 1997, Latvijas derīgie izrakteņi, [Mineral deposits of Latvia], Riga: the University of Latvia, 67.
4. G. Sedmale G., Cimmers A., Sedmalis U., 2009, Charasteristics of illite clay and compositions for porous building ceramics production, Institue of Silicate Materials, Riga Technical Univesity, ISSN 1392 -1231, Chemine Technologija, Nr. 2 (51).
5. A. Salahov, L. Tagirov, R. Salahova, V. Parfenov, N. Ljadov, Поры и прочностные характеристики строительных материалов, [Characterization of building material pore and strength], Строительные материалы Nr. 12, December (2011) pp.25-27.