Alternative-energy car sales tend to fall rapidly after fuel prices peak, according to Kelly Blue Book.

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There are various comparable-data sources--eBay and Kelly Blue Book (for the van) are two examples.

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In fact, car industry experts at Kelly Blue Book actually recommend that car shoppers start with the web.

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Rice's Healthcare Blue Book basically offers blue book prices for medical procedures -- like the " Kelly Blue Book" value for a car that you go into the dealership with to negotiate.

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