1. Sheng S. Report on wind turbine subsystem reliability-a survey of various databases
2. Sheng S Keller J Glinsky C Gearbox reliability collaborative update 2013
3. Stadler K Stubenrauch A Premature bearing failures in wind gearboxes and white etching cracks (WEC) http://evolution.skf.com/category/technology/
4. Tracking the source of gearbox bearing failure;Herr;Windpower engineering & development,2014