- Mechanical recycling of compounded plastic waste for material valorization by briquettingKers, Jaan; Krizan, Peter; Letko, MartinScientific journal of Riga Technical University. Series 1, Material science and applied chemistry2010 / p. 39-44 https://ortus.rtu.lv/science/en/publications/8056
- Mechanical recycling of compounded plastic waste for material valorization by briquettingKers, Jaan; Križan, P.; Letko, M.Baltic Polymer Symposium 2009 : Ventspils, Latvia, September 22-25 : programme and proceedings2009 / p. 22