Appendix B ("Fractals: Self-Similar and Self-Affine Systems") of Goehring, L., Nakahara, A., Dutta, T., Kitsunezaki, S., & Tarafdar, S. (2015). Desiccation cracks and their patterns: Formation and Modelling in Science and Nature. John Wiley & Sons. URL: https://doi.org/10.1002/9783527671922.app2
The following publicly available resources may be useful:
"Self-similarity and panorama of self-affinity" by Mandelbrot. PDF: https://courses.physics.ucsd.edu/2019/Spring/physics235/Madelbrot%20E6%20-OV%20on%20Self%20Affinity.pdf
Appendix B ("Fractals: Self-Similar and Self-Affine Systems") of Goehring, L., Nakahara, A., Dutta, T., Kitsunezaki, S., & Tarafdar, S. (2015). Desiccation cracks and their patterns: Formation and Modelling in Science and Nature. John Wiley & Sons. URL: https://doi.org/10.1002/9783527671922.app2