I’m having a lot of trouble handling invasions. I can’t contain them and my stones wind up getting devoured. My strategy is lacking but my tactics are killing me. Any suggestions for a book or two to help improve my defenses?

Might help if you could post an example of this from one of your games.

That said, a few things to consider:

1. Often the cause of failing to capture an invading stone in your territory results from misjudging whether or not the territory is in fact yours. Players often feel that they have more control of an area than they do.

2. Not all invasions can be captured. And sometimes it is most advantageous to threaten to capture an invasion knowing that it can run to safety. The idea being that the stones you get to play chasing it to safety allow you to build up another advantage.

3. Shape. This includes poor shape in the moyo's walls that creates cut points your opponent can use to get out and not knowing enough about the shapes your opponent could make to live. With the latter, you can't prevent your opponent from making two eyes and living.

4. Reading skills. Capturing an invading stone requires significant reading skills. So, even if you know everything for the previous point, you may not be able to implement it.

Recommendations are tricky without a clearer idea of your ability level, but the book that I found most helpful on this topic is Attacking and Defending Moyos. Others should jump in if they disagree, but my sense is that this book is most useful in the SDK, possible the very low DDK range. I read it when I had probably just reached the SDK level on the KGS scale. I still struggle to implement the various strategies correctly for the four reasons described above, but trying has allowed me to identify where my deficits are. Sometimes it's not always clear to me which deficit is the issue, but when that happens it is easily solved by posting the game here!

It's also important to keep in mind that dealing with invasions is also just a fundamental dynamic of the game. Invading is a standard tactic and even professionals misjudge the quality of the shape of their moyo or fail to find exactly the right sequence necessary to prevent life.

I'm not sure if a book is the right direction for this. It's easy to learn from examples, so having a few of your games reviewed could be better. You could also try the same invasions yourself, and see how the opponents refute. Tactics in particular need experience rather than theory.