If you want to include a reference mentioning tea tree oil as a common folk remedy but not giving directions instructions advice or amounts to use go for it However keep in mind that past versions of that parargraph had been edited to take out medical advice added by well meaning editors who thought giving exact instructions on how to use tea tree oil to treat ringworm was appropriate That we can not leave in because it constitutes medical advice Past versions of this article and other articles on pet medical issues such as ticks often wind up with edits telling people to use this household cleanser or that easily obtained chemical and more often than not that advice is foolish and dangerous I probably could have softened the wording a bit but I was getting tired of editors using articles on topics such as these to insert potentially disasterous advice Whatever you link to be sure it meets the reliability standard and be mindful of the potential harm to people and animals that a link to an casual recipe for a cure could cause I m sure there are many decent references and quotes you could find to support the efficacy of tea tree oil as a folk remedy and the theory behind it As to Wikipedia s own article one wikipedia article can not cite another to reference a statement but if that article already has a reference that supports the contention of it s efficacy well by all means nab that citation