Passbooks: - National Learning Corporation has been a leading publisher of test-preparation Passbooks(R) for more than 50 years, with 6,000 titles available across 22 series. The Career Examination Series features thousands of titles designed to prepare test candidates for their upcoming civil-service job exam. Each book in the Career Series offers practice through multiple-choice questions and answers in relevant subject areas, as well as informative texts to aid in understanding the study material.