вторичный сектор . Koolisõnastikud 2005–2010. Estonian Language Institute, Sõnaveeb 2026.
https://sonaveeb.ee/search/unif//kool_KV/%D0%B2%D1%82%D0%BE%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D0%B9%20%D1%81%D0%B5%D0%BA%D1%82%D0%BE%D1%80/1/rus (30.08.2026)

вторичный сектор . Koolisõnastikud 2005–2010. Estonian Language Institute, Sõnaveeb 2026.
https://sonaveeb.ee/search/unif//kool_KV/%D0%B2%D1%82%D0%BE%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D0%B9%20%D1%81%D0%B5%D0%BA%D1%82%D0%BE%D1%80/1/rus (30.08.2026)