CAHYASARI, A.; BUDIYANTO, M.; SUSIYAWATI, E. USING PROJECT-BASED LEARNING WORKSHEET WITH WASTE WATER TREATMENT THEME TO PRACTICE STUDENT’ PROBLEM-SOLVING SKILLS. PENSA: E-JURNAL PENDIDIKAN SAINS, v. 8, n. 2, p. 110-114, 1 jul. 2020.