@article {28125,
	title = {Validation methodologies and their impact in construction productivity research},
	journal = {Journal of Construction Engineering and Management},
	volume = {140},
	year = {2014},
	url = {https://doi.org/10.1061/(ASCE)CO.1943-7862.0000882},
	author = {Jiali Liu and Arash Shahi and Carl T Haas and Paul Goodrum and Carlos H Caldas}
}