for OTA you can have a look at chapter 2.8.2 of "Modern Analog Filter Analysis and Design: A Practical Approach" by Rabin Raut and M. N. S. Swamy
regarding filter realization using OTA, see chapter 5.9 of the same book.
Other interesting chapters are:
-5.10.4.2
-7.1.1
-7.4.1
-7.5
-7.5.4
-9.3.2
-9.4.2.3