The following books have been added to the bibliography.
First I read O’Shea’s “Poincare”; it’s way past time it showed up in the bibliography. Then I bought Weeks and “Ricci” based on O’Shea’s “further reading”. One is high school – barely – and the other is high research. I’ve skimmed Weeks once and have settled down to read it again. “Ricci” is beyond me, as I expected.
While trying to find out how a surface could be given a geometry in which it had constant curvature, I ended up at the back of O’Neill; he’s an old favorite. While trying to sort out topological and differential structures, I took another look at “Instantons” – right up there with “Ricci Flow” – and then discovered why I had bought Bloch in the first place: I could read him.