6An i bal De Almeida, Simon I~irzel, Carlos Patro, Joo Fong, Elisabeth D ti tschke. Energy-efficient elevators and escalators in Europe: An analysis of energy efficiency potentials and policy measures[J]. Energy and Buildings, 2013, 59: 93-103.
7European Standard EN 81-80: Safety rules for the construction and installation of lifts--Existing lifls--Part 80: Rules for the improvement of safety of existing passenger and goods passenger lifts.