Identifying empirical studies for mixed studies reviews: The mixed filter and the automated text classifier. - El Sherif, Reem; Langlois, Alexis; Pandu, Xiao; Nie, Jian-Yun; Thomas, James; Hong, Quan Nha; Pluye, Pierre; Granikov, Vera; Pluye, Piere (Education for Information, 2020)