Hell, Stefan W. Optical Nanoscopy, Max Planck Institute for Medical Research, Max Planck Society;
https://doi.org/10.1007/978-3-030-16638-0_1 (Any fulltext)
https://link.springer.com/content/pdf/10.1007%2F978-3-030-16638-0_1.pdf (Any fulltext)
Sahl, S. J., & Hell, S. W. (2019). High-resolution 3D light microscopy with STED and RESOLFT. In J. F. Bille (Ed.), High resolution imaging in microscopy and ophthalmology (pp. 3-32). Cham: Springer. doi:10.1007/978-3-030-16638-0_1.