1. [1] BBC: Shanghai window cleaning cradle swings out of control, http://www.bbc.com/news/world-asia-china-32176401.
2. [2] BBC: Window washers rescued from high up World Trade Center, http://www.bbc.com/news/world-us-canada-30028969.
3. [3] H. Zhang, J. Zhang, G. Zong, W. Wang, R. Liu: Sky cleaner 3: a real pneumatic climbing robot for glass-wall cleaning, Robotics & Automation Magazine, IEEE, 13:1 (2006), 32-41.
4. [4] H. Zhang, J. Zhang, G. Zong: Effective pneumatic scheme and control strategy of a climbing robot for class wall cleaning on high-rise buildings, International Journal of Advanced Robotic Systems, 3:2 (2006), 183-190.
5. [5] H. Zhang, J. Zhang, G. Zong: Requirements of glass cleaning and development of climbing robot systems, in Intelligent Mechatronics and Automation, 2004. Proceedings. 2004 International Conference on, Chengdu, 2004, 101-106.