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 General Aptitude and Abilities Series (CS) provides functional, intensive test practice and drill in the basic skills and areas common to many civil service, general aptitude or achievement examinations necessary for entrance into schools or occupations. Each book offers practice through multiple-choice questions and answers.