1. 1) Cameron, B. A. Detergent considerations for consumers: laundering in hard water – How much extra detergent is required? J. Extension 49, 1-11 (2011).
2. 2) Abeliotis, K.; Candan, C.; Amberg, C.; Ferri, A.; Osset, M.; Owens, J.; Stamminger, R. Impact of water hardness on consumers’ perception of laundry washing result in five European countries. Int. J. Consumer Stu. 39, 60-66 (2015).
3. 3) Okada, N.; Fujii, T.; Okuyama, H. Removal of Oily Soils (Part 2) The relation of yellowing and residue with hard ions on fabrics. J. Home Econ. Jpn. 27, 215-220 (1976).
4. 4) Okada, N.; Fujii, T.; Minagawa, M. Removal of oily soils (Part 4) Effect of fatty acid soaps on removal of oily soils and yellowing of the fabrics washed in hard water. J. Home Econ. Jpn. 35, 322-330 (1984).
5. 6) Cox M. F.; Matheson, K. L. Interaction between linear alkylbenzene sulfonate and water hardness ions. II. Reducing hardness sensitivety by the addition of micelle promotion agents. J. Am. Oil Chem. Soc. 62, 1396-1399 (1985).