Балтруков, Николай Николаевич. Электротехника и электроника [Электронный ресурс]: учебное пособие (теория) / Н. Н. Балтруков, Ю. Д. Кочетков. — Электрон. текстовые дан. (1 файл : 2,94 Мб). — СПб., 2011. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Текстовый файл. — Adobe Acrobat Reader 6.0. — <URL:http://elib.spbstu.ru/dl/2102.pdf>.
| Period | Read | Copy | Open | Total | ||
|---|---|---|---|---|---|---|
| Year 2012 | Quarter 1 | 0 | 0 | 3 | 0 | 3 |
| Quarter 2 | 0 | 0 | 6 | 0 | 6 | |
| Quarter 3 | 0 | 0 | 21 | 0 | 21 | |
| Quarter 4 | 13 | 0 | 64 | 0 | 77 | |
| Year 2013 | Quarter 1 | 5 | 0 | 20 | 0 | 25 |
| Quarter 2 | 30 | 0 | 21 | 0 | 51 | |
| Quarter 3 | 27 | 0 | 8 | 0 | 35 | |
| Quarter 4 | 46 | 0 | 39 | 0 | 85 | |
| Year 2014 | Quarter 1 | 35 | 0 | 15 | 0 | 50 |
| Quarter 2 | 44 | 0 | 34 | 0 | 78 | |
| Quarter 3 | 31 | 0 | 24 | 0 | 55 | |
| Quarter 4 | 39 | 0 | 33 | 0 | 72 | |
| Year 2015 | Quarter 1 | 30 | 0 | 16 | 0 | 46 |
| Quarter 2 | 26 | 0 | 23 | 0 | 49 | |
| Quarter 3 | 85 | 0 | 73 | 0 | 158 | |
| Quarter 4 | 108 | 1 | 57 | 0 | 166 | |
| Year 2016 | Quarter 1 | 59 | 0 | 41 | 0 | 100 |
| Quarter 2 | 58 | 0 | 30 | 0 | 88 | |
| Quarter 3 | 40 | 0 | 30 | 0 | 70 | |
| Quarter 4 | 41 | 0 | 113 | 0 | 154 | |
| Year 2017 | Quarter 1 | 14 | 0 | 89 | 0 | 103 |
| Quarter 2 | 18 | 0 | 185 | 0 | 203 | |
| Quarter 3 | 15 | 0 | 124 | 0 | 139 | |
| Quarter 4 | 18 | 0 | 191 | 0 | 209 | |
| Year 2018 | Quarter 1 | 40 | 0 | 176 | 0 | 216 |
| Quarter 2 | 15 | 0 | 252 | 0 | 267 | |
| Quarter 3 | 26 | 0 | 93 | 0 | 119 | |
| Quarter 4 | 31 | 0 | 75 | 0 | 106 | |
| Year 2019 | Quarter 1 | 19 | 0 | 71 | 0 | 90 |
| Quarter 2 | 13 | 0 | 87 | 0 | 100 | |
| Quarter 3 | 28 | 0 | 53 | 0 | 81 | |
| Quarter 4 | 10 | 0 | 98 | 0 | 108 | |
| Year 2020 | Quarter 1 | 9 | 0 | 64 | 0 | 73 |
| Quarter 2 | 47 | 0 | 19 | 0 | 66 | |
| Quarter 3 | 28 | 0 | 7 | 0 | 35 | |
| Quarter 4 | 28 | 0 | 47 | 0 | 75 | |
| Year 2021 | Quarter 1 | 37 | 0 | 139 | 0 | 176 |
| Quarter 2 | 16 | 0 | 136 | 0 | 152 | |
| Quarter 3 | 14 | 0 | 153 | 0 | 167 | |
| Quarter 4 | 23 | 0 | 134 | 0 | 157 | |
| Year 2022 | Quarter 1 | 21 | 0 | 96 | 0 | 117 |
| Quarter 2 | 34 | 0 | 140 | 0 | 174 | |
| Quarter 3 | 18 | 0 | 75 | 0 | 93 | |
| Quarter 4 | 13 | 0 | 142 | 0 | 155 | |
| Year 2023 | Quarter 1 | 16 | 0 | 113 | 0 | 129 |
| Quarter 2 | 24 | 1 | 146 | 0 | 171 | |
| Quarter 3 | 10 | 0 | 74 | 0 | 84 | |
| Quarter 4 | 19 | 0 | 143 | 0 | 162 | |
| Year 2024 | Quarter 1 | 10 | 0 | 136 | 0 | 146 |
| Quarter 2 | 26 | 0 | 154 | 0 | 180 | |
| Quarter 3 | 16 | 0 | 79 | 0 | 95 | |
| Total | 1,373 | 2 | 4,162 | 0 | 5,537 | |