The first strongly implies that there are canonical Gnostic texts and that the interest is in only the non-canonical variety. The second indicates texts that a

The first strongly implies that there are canonical Gnostic texts and that the interest is in only the non-canonical variety. The second indicates texts that are both non-canonical and Gnostic. Doesn't rule out all misinterpretations but at least doesn't imply them. Probably the best version of this that can be accomplished with small changes. Third states that the interest is in texts that are either non-canonical or gnostic without a requirement that they be both of those things (a little similar to the first but without drawing as much attention to the implication of canonical gnostic texts) The fourth defines Gnostic texts as synonymous with non-canonical texts.