References

1
Mullis, I.V.S., Martin, M.O., & Foy, P. (2016). TIMSS Advanced 2015 International Results in Advanced Mathematics and Physics. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.
2
Mullis, I.V.S., Martin, M.O., & Foy, P. (2016). TIMSS 2015 International Results in Mathematics. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.
3
Mullis, I.V.S., Martin, M.O., & Foy, P. (2016). TIMSS 2015 International Results in Science. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.
4
Martin, M. O., Mullis, I. V. S., & Hooper, M. (Eds.). (2016). Methods and Procedures in TIMSS 2015. Retrieved from http://timssandpirls.bc.edu/publications/timss/2015-methods.html