I know they are included with the download bits, do you still have your 11.5.3 .zip?
You can find the NPM 11.5.2 Administrator Guide here:
That PDF was in the "Using NPM" section in the middle column when visiting the Success Center link below:
I looked for some other versions but it appears they are a bit out of the way at the moment.
There is a bit of a transition and re-organization going on with the Success Center right now, which I might add has been very helpful and is going to make everything much easier to find in the long run.
I would kindly suggest leaving feedback using the "Was this article helpful?" section to the right in the Success Center link above, as I can attest the organization is paying VERY close attention to customer feedback at the moment. You can also e-mail Customer Success here: email@example.com
I still had the 11.5.3 zip file but the documents are for 11.5.2 so that link above should work for you.