HelaluddinH., MannahaliM., PurwatiD., AlamsyahA., и WijayaH. «An Investigation into the Effect of Problem-Based Learning on Learners’ Writing Performance, Critical and Creative Thinking Skills». Journal of Language and Education, т. 9, вып. 2, июнь 2023 г., сс. 101-17, doi:10.17323/jle.2023.14704.