Леун, Е.В. 2023. Fundamentals of design of jet-drop optical systems for three-coordinate measurements of electric, magnetic and gravitational field strengths by the pendant drop method. Part 1. Omsk Scientific Bulletin. 1(185) (Feb. 2023), 114–121. DOI:https://doi.org/10.25206/1813-8225-2023-185-114-121.