Madalpingelised elektripaigaldised. Osa 5-56, Elektriseadmete valik ja paigaldamine ; Turvasüsteemid [Võrguteavik] = Low-voltage electrical installations. Part 5-56, Selection and erection of electrical equipment ; Safety services (IEC 60364-5-56:2018)2019 https://www.ester.ee/record=b5251705*est