Sholikah, Rofi'atus, and Puji Rahayu. “VALIDITAS LEMBAR KERJA SISWA (LKS) BERBASIS PROBLEM SOLVING PADA MATERI PERSAMAAN LINGKARAN: Studi Kasus Di SMK PGRI 2 Tuban”. Prosiding SNasPPM, vol. 6, no. 1, Aug. 2021, pp. 544-50, http://prosiding.unirow.ac.id/index.php/SNasPPM/article/view/816.