1. M. Iakovlev , Doctoral thesis, Aalto University, Finland, 2011
2. S. A. Rydholm , Pulping Processes, John Wiley & Sons Inc., London, 1965, p. 456
3. S. A. Rydholm , Pulping Processes, John Wiley & Sons Inc., London, 1965, p. 540
4. S. A. Rydholm , Pulping Processes, John Wiley & Sons Inc., London, 1965, pp. 488–490
5. S. A. Rydholm , Pulping Processes, John Wiley & Sons Inc., London, 1965, p. 186