APA (7th ed.) Citation

Skaalvik, E. M., & Valas, H. Relations Among Achievement, Self-Concept, and Motivation in Mathematics and Language Arts: A Longitudinal Study.

Chicago Style (17th ed.) Citation

Skaalvik, Einar M., and Harald Valas. Relations Among Achievement, Self-Concept, and Motivation in Mathematics and Language Arts: A Longitudinal Study.

MLA (9th ed.) Citation

Skaalvik, Einar M., and Harald Valas. Relations Among Achievement, Self-Concept, and Motivation in Mathematics and Language Arts: A Longitudinal Study.

Warning: These citations may not always be 100% accurate.