APA   Click to copy
Greiff, S., & Kyllonen, P. (2016). Contemporary assessment challenges. The measurement of 21st century skills. Special issue. Applied Measurement in Education. https://doi.org/10.1080/08957347.2016.1209209

Chicago/Turabian   Click to copy
Greiff, S., and P. Kyllonen. “Contemporary Assessment Challenges. The Measurement of 21st Century Skills. Special Issue.” Applied Measurement in Education (2016).

MLA   Click to copy
Greiff, S., and P. Kyllonen. “Contemporary Assessment Challenges. The Measurement of 21st Century Skills. Special Issue.” Applied Measurement in Education, 2016, doi:10.1080/08957347.2016.1209209.

@article{greiff2016a,
  title = {Contemporary assessment challenges. The measurement of 21st century skills. Special issue},
  year = {2016},
  journal = {Applied Measurement in Education},
  doi = {10.1080/08957347.2016.1209209},
  author = {Greiff, S. and Kyllonen, P.}
}