@article{spurr_barac-nieto_maksud_1977, 
  title={Efficiency and daily work effort in sugar cane cutters.}, 
  volume={34}, 
  DOI={10.1136/oem.34.2.137}, 
  publisher={BMJ}, 
  author={Spurr and Barac-Nieto and Maksud}, 
  year={1977}, 
  month={May}
  }