Electronics----pseudo-resistors

I am an undergraduate electrical engineering student and currently doing a research on FET pseudo-resistors which are high value resistors that are implemented using mosfets biased in their weak inversion regions. I searched a lot these days and I couldnt find a good source that can explain to me about the mechanism of pseudo-resistors. So I was wondering if anybody here can suggest a good book or article that can give me good insight of Pseudo-resistors. I will appreciate every single response.