Funding for this research was provided by:
North Dakota Center for Tobacco Prevention and Control Policy (G15-79, G15-83, G15-113)
Text and Data Mining valid from 2018-11-26
Received: 4 June 2018
Accepted: 30 August 2018
First Online: 26 November 2018
Ethics approval and consent to participate
: This study was approved by the North Dakota State University Institutional Review Board (Protocol #PH16291).
: Not applicable.
: The authors declare that they have no competing interests.
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