сілтеме: https://moodle.enu.kz/pluginfile.php/253374/mod_lesson/intro/%D0%94%D3%99%D1%80%D1%96%D1%81%20%209.pdf
Презентация:
https://moodle.enu.kz/pluginfile.php/253374/mod_lesson/intro/9-%D0%BC%D0%B0%D1%81%D1%81%D0%B8%D0%B2.ppsx
