Aini, Septi Dariyatul, et al. “WRITTEN MATHEMATICAL COMMUNICATION SKILLS ON OPEN-ENDED PROBLEMS: IS IT DIFFERENT BASED ON THE LEVEL OF MATHEMATICS ABILITY?”. MaPan : Jurnal Matematika Dan Pembelajaran, vol. 8, no. 2, Dec. 2020, pp. 179-04, doi:10.24252/mapan.2020v8n2a2.