Dorothy M. Callahan Books

Under Christopher's hat

By Dorothy M. Callahan

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During a very busy vacation day Christopher wears the hat of the milkman, fireman, detective, and cowboy.

Julie Krone, a winning jockey

By Dorothy M. Callahan

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Discusses the childhood, education, early riding career, major races, records, titles, views, and personal life of jockey Julie Krone.

Thoroughbreds

By Dorothy M. Callahan

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Discusses the breed of horse known as thoroughbred and follows a new colt from birth to the day of its maiden race.

Jimmy, the story of the young Jimmy Carter

By Dorothy M. Callahan

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A biography of the 39th President stressing the events of his childhood and Naval career.

Jimmy, the story of the young Jimmy Carter

By Dorothy M. Callahan

Average: 0.00, 0 Ratings

A biography of the 39th President stressing the events of his childhood and Naval career.

Ruffian

By Dorothy M. Callahan

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Presents the life of a race horse who successful career was tragically cut short.

How to Convert ISBN-10 to ISBN-13 (and Vice Versa): A Complete Guide

If you’re in the world of books—whether as a publisher, librarian, bookseller, or avid collector—you’ve likely come across the terms ISBN-10 and ISBN-13. Understanding these formats and knowing how to convert between them is essential for maintaining consistency and compatibility in book records. In this post, we’ll cover everything you need to know about ISBN conversions, step by step.

What is an EAN and How Does it Relate to an ISBN?

If you’ve ever purchased a product online or in a store, you’ve likely come across a barcode. Behind these barcodes lies a standardized system that makes modern commerce possible. Two key codes often encountered are the EAN (European Article Number) and ISBN (International Standard Book Number). But what are they, how are they connected, and why are they so crucial? Let’s explore.