Instructional Objectives Exchange. (1972). Math: Data relationships : graphs, ratios and proportions, statistics and probability, grades K-9 (Rev. ed.).
Lua i Stíl Chicago (17ú heag.)Instructional Objectives Exchange. Math: Data Relationships : Graphs, Ratios and Proportions, Statistics and Probability, Grades K-9. Rev. ed. Los Angeles, Calif, 1972.
Lua MLA (8ú heag.)Instructional Objectives Exchange. Math: Data Relationships : Graphs, Ratios and Proportions, Statistics and Probability, Grades K-9. Rev. ed. 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.