I bought this years ago. It was part of his invisible series...Invisible Gemstone, Invisible Tarot, Invisible Readings. I have them all on a hard drive somewhere. They are not physical books, but ebooks.
They all use methods of having the sitter visualize something. The visualizations are compelling. The theme of this series is readings with no props other than two hearts/minds working together. They are well done approaches that involve the sitter emotionally.
Of the three, I still use the Invisible Gemstone sometimes. I used Invisible Tarot for a bit but prefer a physical pack of cards for tarot reading, though it should be mentioned that physical cards are introduced at a point in the Invisible Tarot approach.
One should not take recommendations from a magician/illusionist forum. They are mostly talkers there, getting excited about the new mentalism guru or hot book that will make them a great reader overnight. They are quite happy if they can use word tricks or other magic-tricky methods to get "hits". They are best left alone to their own happy little world. There are a few actual readers there but most are fantasy-prone puzzle junkies.
Enrique is a different sort. Though he does hang there rarely you can see his approach to readings by searching his name and looking at his work.
I think anyone here considering Enrique's work should look at his public writings before buying anything. He is a poet at heart and it shows in his work. If it is for you that is good.
Edit added: Here he is on this forum...
http://www.tarotforum.net/showthread.php?t=99758
http://www.tarotforum.net/showthread.php?t=100136
http://www.tarotforum.net/showthread.php?t=100540
http://www.tarotforum.net/showthread.php?t=100904
http://www.tarotforum.net/showthread.php?t=101322
http://www.tarotforum.net/showthread.php?t=101788
Enrique has what reader's need...a good heart. If your heart is right and touches the sitter in a positive way you don't need anyone's method but your own.