Robuta

https://www.bls.gov/opub/ted/2012/ted_20121001_data.htm

https://www.bls.gov/opub/mlr/1997/article/multifactor-productivity-in-refrigeration-and-heating-equipment-industry.htm

https://www.bls.gov/k12/productivity-101/content/what-is-available-and-how-do-i-access-it/multifactor-productivity.htm