Четвериков, Сергей Федорович. Информационно-измерительная система для изучения статистических свойств и суточно-сезонных вариаций интенсивности естественного ОНЧ радиошума [Электронный ресурс] = Using the information and measurement system to study statistical characteristics and daily and seasonal variation in the intensity of VLF atmospheric radio noise / С.Ф. Четвериков. — (Приборы, информационно-измерительные системы). — Электрон. текстовые дан. (1 файл : 352 Кб) // Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Сер.: Информатика. Телекоммуникации. Управление = St. Petersburg state polytechnical university journal. Computer science. Telecommunications and control systems: научное издание. – Санкт-Петербург. – 2014. – № 3 (198). — Загл. с титул. экрана. — Электронная версия печатной публикации. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Текстовый файл. — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/4682.pdf>.
| Period | Read | Copy | Open | Total | ||
|---|---|---|---|---|---|---|
| Year 2014 | Quarter 3 | 14 | 0 | 8 | 0 | 22 |
| Quarter 4 | 15 | 0 | 6 | 0 | 21 | |
| Year 2015 | Quarter 1 | 18 | 0 | 7 | 0 | 25 |
| Quarter 2 | 12 | 0 | 4 | 0 | 16 | |
| Quarter 3 | 15 | 0 | 1 | 0 | 16 | |
| Quarter 4 | 16 | 0 | 14 | 0 | 30 | |
| Year 2016 | Quarter 1 | 5 | 0 | 3 | 0 | 8 |
| Quarter 2 | 5 | 0 | 5 | 0 | 10 | |
| Quarter 3 | 9 | 0 | 4 | 0 | 13 | |
| Quarter 4 | 15 | 0 | 14 | 0 | 29 | |
| Year 2017 | Quarter 1 | 11 | 0 | 20 | 0 | 31 |
| Quarter 2 | 5 | 0 | 7 | 0 | 12 | |
| Quarter 3 | 8 | 0 | 10 | 0 | 18 | |
| Quarter 4 | 7 | 0 | 10 | 0 | 17 | |
| Year 2018 | Quarter 1 | 7 | 0 | 45 | 0 | 52 |
| Quarter 2 | 8 | 0 | 23 | 0 | 31 | |
| Quarter 3 | 8 | 0 | 11 | 0 | 19 | |
| Quarter 4 | 8 | 0 | 8 | 0 | 16 | |
| Year 2019 | Quarter 1 | 6 | 0 | 4 | 0 | 10 |
| Quarter 2 | 5 | 0 | 7 | 0 | 12 | |
| Quarter 3 | 5 | 0 | 18 | 0 | 23 | |
| Quarter 4 | 4 | 0 | 11 | 0 | 15 | |
| Year 2020 | Quarter 1 | 18 | 0 | 15 | 0 | 33 |
| Quarter 2 | 13 | 0 | 0 | 0 | 13 | |
| Quarter 3 | 14 | 0 | 0 | 0 | 14 | |
| Quarter 4 | 9 | 0 | 13 | 0 | 22 | |
| Year 2021 | Quarter 1 | 11 | 0 | 6 | 0 | 17 |
| Quarter 2 | 8 | 0 | 11 | 0 | 19 | |
| Quarter 3 | 11 | 0 | 10 | 0 | 21 | |
| Quarter 4 | 4 | 0 | 3 | 0 | 7 | |
| Year 2022 | Quarter 1 | 9 | 0 | 9 | 0 | 18 |
| Quarter 2 | 8 | 0 | 11 | 0 | 19 | |
| Quarter 3 | 9 | 0 | 3 | 0 | 12 | |
| Quarter 4 | 9 | 0 | 3 | 0 | 12 | |
| Year 2023 | Quarter 1 | 8 | 0 | 6 | 0 | 14 |
| Quarter 2 | 6 | 0 | 4 | 0 | 10 | |
| Quarter 3 | 2 | 0 | 2 | 0 | 4 | |
| Quarter 4 | 5 | 0 | 8 | 0 | 13 | |
| Year 2024 | Quarter 1 | 4 | 0 | 3 | 0 | 7 |
| Quarter 2 | 12 | 0 | 18 | 0 | 30 | |
| Quarter 3 | 3 | 0 | 7 | 0 | 10 | |
| Quarter 4 | 18 | 0 | 12 | 0 | 30 | |
| Year 2025 | Quarter 1 | 24 | 0 | 17 | 0 | 41 |
| Quarter 2 | 10 | 0 | 0 | 0 | 10 | |
| Quarter 3 | 0 | 0 | 0 | 0 | 0 | |
| Total | 421 | 0 | 401 | 0 | 822 | |