Sigurður Gylfi Magnusson 
Design of Analog Multipliers with Operational Amplifiers [PDF ebook] 

Design of analog multipliers discusses what an analog multiplier and its related types is, how different types of analog multipliers are implemented with analog two to one multiplexers and op-amps, and how the types of analog multipliers are implemented with transistors and op-amps. Describing forty-eight analog multiplier circuits, book explains six building blocks as integrator, comparator, switch, low pass filter, peak detector and sample & hold circuit. All analog multiplier circuits presented in this book use a maximum of four operational amplifiers which will enable the readers to simulate the multipliers with minimum number of components and use for their application at low cost.