Ah ha! That explains it. The second book is obtained from the Experiment in Djose Temple (I did that during my last game) and by process of elimination the first book is from the Den of Woe. *sulky face* I got lucky enough to miss the first sphere (chasing Ormi & Logos through Mushroom Rock) during my first game so I didn't get to complete the Den of Woe. That's why I didn't get the first book. I have all of the Crimson Spheres so far (just need the ones in Via Infinito) so I'm good to go!

Thanks muchly!