No I'm afraid I don't have the literature. I've repeated what was explained to me by my cardiologist at a recent visit.
I had mine for 10 years before I was diagnosed hypo. As soon as I began thyroid treatment they started to disappear. Certain things will aggravate them ( as explained by the cardiologist!)
Caffeine.....big no no!! Try decaf tea and coffee
Decongestants that contain Ephedrine.
Caffeinated Cola drinks.
Heavily spiced food.
They are ALL stimulants and will encourage ectopic beats if you are prone to them. Cutting These out of your diet or limiting them could help symptoms.
I cut alcohol out years ago and caffeine and decongestants........
You may find that when you speed your heart up by cycling or something equally as unappealing you over ride the ectopic beat and a normal rhythm resumes. When I first had mine I bought an exercise bike and would get on it as they started. It did help but an adequate dose of Levo has done more to dissipate them than anything else. My tolerance of the above stimulants has increased remarkablySince being on adequate Levo.
Hope this is helpful.