Lesson over 4.1: https://drive.google.com/file/d/1BbrXvfr66ftRoTWMdccf8GgRzEK0U1J3/view
Lesson over 4.2: https://drive.google.com/file/d/1mYekuFEJCuPAPpSHlh59BZdhWvPgakzF/view
Lesson over 4.3: part 1 https://youtu.be/QviLSzNxgSw
part 2 https://youtu.be/ak1-TILsSGk
Lesson over 4.4: https://drive.google.com/file/d/1BF7gG3zAhPGzulqZAzXejP_r_Mct5pkl/view
Lesson over 4.5: https://drive.google.com/file/d/1vbq-89gqlFOx8miGS7Z-aAu6rzcswJIo/view
Lesson over 5.6: https://drive.google.com/file/d/1FTLs_W5MTFHjxGlQk0V-cQn7kUTPONcB/view