I used only the "Hitori de Tokkun" book from Koguma-kai, and I made copies of it. There are no markings. The other books are unused. Entrance Exam Preparation Materials for Recommendations Tsukuba University Elementary School Entrance Exam Preparation: Figures Summary A Publisher: Kyoiku Tosho 21 (Wakagiri 21) Price: 1000 yen + tax National Mock Exam Past Questions Gakugei University Oizumi, Koganei, Setagaya, Tsukuba University Elementary School Entrance Exam Preparation Problem Collection Publisher: Kyoiku Tosho 21 (Wakagiri 21) Price: 1500 yen + tax School-Specific Hitori de Tokkun: Tsukuba University Elementary School [Advanced Edition] Publisher: Koguma-kai Price: 840 yen (tax included)