Query4All.com
Index of/periscope
Data generated from past analysis.
https://isaacphysics.org/questions/periscope
https://isaacphysics.org/questions/periscope
https://cran.r-project.org/src/contrib/Archive/periscope/
https://collegedunia.com/exams/periscope-physics-articleid-1577
https://www.periscopeholdings.com/assets/why-periscope/
https://www.quora.com/In-a-prismatic-Periscope-what-happens-to-light-rays-which-strike-the-surface-of-the-prism-at-an-incidence-angle-that-is-greater-or-less-than-the-critical-angle-Will-these-light-rays-enter-our-eyes-and-help-us-see-an
https://en.wikipedia.org/wiki/Periscope
https://byjus.com/physics/periscope/
https://gus-periscopes.com/wp-content/uploads/2021/05/GuS-HISTORY-PERISCOPES.pdf
https://www.embibe.com/questions/What-is-a-periscope%3F-Explain-the-working-of-a-periscope-that-uses-two-right-angled-prisms./EM9028871