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2. Common Core State Standards Initiative (2010). Mathematics. Retrieved 6 June 2013 from http://www.corestandards.org/Math.
3. Common Core State Standards Initiative (2013a). High School Publishers’ Criteria for the Common Core State Standards for Mathematics. Retrieved 27 Apr 2013 from http://www.corestandards.org/resources .
4. Common Core State Standards Initiative (2013b). Publishers’ Criteria for the Common Core State Standards for Mathematics, Grades K-8. Retrieved 27 Apr 2013 from http://www.corestandards.org/resources .
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