@article{hu_frey_washburn_2016, title={Comparison of vehicle-specific fuel use and emissions models based on externally and internally observable activity data}, DOI={10.3141/2570-04}, number={2570}, journal={Transportation Research Record}, author={Hu, J. C. and Frey, H. C. and Washburn, S. S.}, year={2016}, pages={30–38} } @article{graver_frey_hu_2016, title={Effect of biodiesel fuels on real-world emissions of passenger locomotives}, volume={50}, DOI={10.1021/acs.est.6b03567}, number={21}, journal={Environmental Science & Technology}, author={Graver, B. M. and Frey, H. C. and Hu, J. C.}, year={2016}, pages={12030–12039} } @article{hu_frey_sandhu_graver_bishop_schuchmann_ray_2014, title={Method for modeling driving cycles, fuel use, and emissions for over snow vehicles}, volume={48}, DOI={10.1021/es501164j}, number={14}, journal={Environmental Science & Technology}, author={Hu, J. C. and Frey, H. C. and Sandhu, G. S. and Graver, B. M. and Bishop, G. A. and Schuchmann, B. G. and Ray, J. D.}, year={2014}, pages={8258–8265} }