1 Center for Tobacco Control Research & Education, Suite 366 Library, 530 Parnassus Avenue, University of California San Francisco, San Francisco, CA 94143-1390, USA. Electronic address: jesse.elias@ucsf.edu.
2 Center for Tobacco Control Research & Education, Suite 366 Library, 530 Parnassus Avenue, University of California San Francisco, San Francisco, CA 94143-1390, USA. Electronic address: yogi.hedlin@ucsf.edu.
3 Center for Tobacco Control Research & Education, Suite 366 Library, 530 Parnassus Avenue, University of California San Francisco, San Francisco, CA 94143-1390, USA. Electronic address: benjamin.chaffee@ucsf.edu.
4 Center for Tobacco Control Research & Education, Suite 366 Library, 530 Parnassus Avenue, University of California San Francisco, San Francisco, CA 94143-1390, USA. Electronic address: pamela.ling@ucsf.edu.