It's written by Ray Blanchard and Michael Bailey
Michael Bailey is Professor of Psychology at Northwestern University. His book The Man Who Would Be Queen provides a readable scientific account of two kinds of gender dysphoria among natal males, and is available as a free download here.
faculty.wcas.northwestern.edu/JMichael-Bailey/TMWWBQ.pdf
I hadn't realised his book was available online. I read in Alice Dreger's book Galileo's Middle Finger about the furore following the publication of Bailey's book.
You could argue that everyone in this debate is biased, so the best way to proceed is to read both sides and make your own mind up. That's what I do - in all areas, not just this one. Once you start dismissing one side as biased and refusing to even read what they have to say, it makes you look bigoted.