http://www.tndte.gov.in/site/wp-content/uploads/2016/08/Engineering-physics.pdf
https://www.aurora.ac.in/images/pdf/departments/humanities-and-sciences/engg-phy-lab-manual.pdf
http://www.kthmcollege.ac.in/images/department/download-20172009154149.pdf
http://www.issp.ac.ru/ebooks/books/open/Introduction%20to%20Modern%20Solid%20State%20Phys.pdf
https://link.springer.com/content/pdf/bfm%3A978-3-540-93804-0%2F1.pdf
http://www.fulviofrisone.com/attachments/article/404/Introduction%20to%20Modern%20Optics.pdf
https://www.goodtheorist.science/files/louro_optics.pdf