Lillienberg L, Zock JP, Kromhout H, Plana E, Jarvis D, Toren K. A population-based study on welding exposures at work and respiratory symptoms. Ann Occup Hyg. 2008 Mar;52(2):107-15.
Phanikumar CV, Maitra B. Modeling willingness-to-pay values for rural bus attributes under different trip purposes. JTRF. 2006;45(2):31-44. doi: 10.22004/ag.econ.206787