1. Ahrel, I. (1973) Actual mill experiences 1968–1973 from producing thermomechanical pulp and gained experiences how to optimize the process for different end uses. In: Int. Mech. Pulping Conf. Stockholm, Sweden, Pres. 20.
2. Ahrel, I., Bäck, I. (1970) Thermomechanical pulp at Rockhammar. In: EUCEPA, Proc. Symp. Mech. Pulp 83. Oslo, Norway. pp. 83–91.
3. Ämmälä, A. (2001) Fractionation of thermomechanical pulp in pressure screening. PhD thesis, University of Oulu, ISBN 951-42-5919-X.
4. Amiri, R., Beaulieu, S., Thompson, T., Frith, M. (2016) Optimization of the Mechanical Pulping Process and its Impact on Energy Consumption and Pulp Properties — Mill Investigation. In: Int. Mech. Pulping Conf. Jacksonville, USA. pp. 667–695.
5. Andersson, S. (2011) Low consistency refining of mechanical pulp – process conditions and energy efficiency. Thesis, Mid Sweden University, ISBN 978-91-86694-60-9.