Advertising pioneer Bruce Barton helped Coolidge collect his speeches and writing into a snappy little book ahead of the Republican nominating convention in 1919. Although early records say this was small enough to fit in a shirt pocket, the real book is a little more than six inches tall. Must be a big pocket. Maybe a jacket pocket. You can pick up a copy at online used book stores or eBay, but most of them are in pretty bad shape. The digital copy is easier (and free).