Withdrawal Symptom, Treatment Mechanism, and/or Side Effect? Developing an Explicit Measurement Model for Smoking Cessation Research. - Tonkin SS; Williams TF; Simms LJ; Tiffany ST; Mahoney MC; Schnoll RA; Cinciripini PM; Hawk LW (Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco, 2020)