A Randomized Trial of E Cigarettes versus Nicotine Replacement Therapy New England Journal of Medicine Vapin is twice as effective as nicotine replacement options Vaped Are E Cigarettes the Right Choice? SiOWfa15: Science in Our World: Certainty and Controversy 4 Different Types of E Cigs (Complete Guide) E Cigs Advice E cigarettes more helpful than nicotine replacement treatments for dependent smokers Queen Mary University of London Regulation stacks up for e cigarettes Nature