@article{raikher_rusakov_2001,  title={Viscoelastic ferrogel: dynamic magnetic susceptibilities},  volume={31},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332001000300006},  DOI={10.1590/S0103-97332001000300006},  number={3},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Raikher, Yu. L. and Rusakov, V. V.},  year={2001},  month={Sep},  pages={366–379} }