Whitacre, Ian, Bishop, Jessica Pierson, Lamb, Lisa L.C., Philipp, Randolph A., Schappelle, Bonnie P., and Lewis, Melinda L. Happy and sad thoughts: An exploration of children's integer reasoning. Retrieved from https://par.nsf.gov/biblio/10123556. The Journal of Mathematical Behavior 31.3 Web. doi:10.1016/j.jmathb.2012.03.001.

Whitacre, Ian, Bishop, Jessica Pierson, Lamb, Lisa L.C., Philipp, Randolph A., Schappelle, Bonnie P., & Lewis, Melinda L. Happy and sad thoughts: An exploration of children's integer reasoning. The Journal of Mathematical Behavior, 31 (3). Retrieved from https://par.nsf.gov/biblio/10123556. https://doi.org/10.1016/j.jmathb.2012.03.001

Whitacre, Ian, Bishop, Jessica Pierson, Lamb, Lisa L.C., Philipp, Randolph A., Schappelle, Bonnie P., and Lewis, Melinda L. "Happy and sad thoughts: An exploration of children's integer reasoning". The Journal of Mathematical Behavior 31 (3). Country unknown/Code not available. https://doi.org/10.1016/j.jmathb.2012.03.001. https://par.nsf.gov/biblio/10123556.

@article{osti_10123556,
place = {Country unknown/Code not available}, title = {Happy and sad thoughts: An exploration of children's integer reasoning}, url = {https://par.nsf.gov/biblio/10123556}, DOI = {10.1016/j.jmathb.2012.03.001}, abstractNote = {}, journal = {The Journal of Mathematical Behavior}, volume = {31}, number = {3}, author = {Whitacre, Ian and Bishop, Jessica Pierson and Lamb, Lisa L.C. and Philipp, Randolph A. and Schappelle, Bonnie P. and Lewis, Melinda L.}, }