1. A design of ultra-low noise amplifiers - description of some ultra-low noise AC and DC amplifiers. See the examples here.
2. A white paper about principles and design of ultra-low noise and high bandwidth transimpedance amplifiers. See the examples here.
3. An article in EDN 5/2012 about a design of an ultra-low distortion oscillator, the original paper is here. See the examples here.
4. A white paper about a modified version of the ultra-low distortion oscillator for frequencies below 10 Hz.
5. A detailed explanation of AC modulation in AD24USB.
6. A connection of various sensors to AD24USB.