Forum Moderators: not2easy
Finding these authors has been very random.
It needn't be.
Make contact with publishers specialising in the areas that are of interest to you. You'll find that all of them have press and promotions departments whose job is to get as much publicity for their books as possible.
Publishers will be only too happy to help you in arranging interviews with authors. They (the publishers) will usually be happy to provide a few books to you for promotional use, for example, as prizes in competitions. If it helps increase awareness of the books and can thus aid the increase of book sales, the publishers will be all for it.
Before making contact with any book publishers, I would strongly recommend that you're clear on what it is you want from them. Go in armed with a solid plan. Justify to them why they should work with you; tell them what you can do for them. Ask "I would like such and such. Is this possible?" Sound weak, vague and indecisive and you'll not get anywhere.
Once you are known to the promotional/press team you'll find that from then on they'll make contact with you whenever they've got something new they think you might be of interest to you. I'm sure you'll appreciate the benefit of that.
Syzygy
FH