Tim Swords is an olympic weightlifting coach and this is a 7 week squat program he employs. It can be used for the front squat or the back squat.
The primary squat stance is worked twice per week, while the alternate squat stance is worked once per week. If you want to focus on back squats, you can simply replace front squats with back squats and vice versa so you are back squatting twice weekly.
Tim Swords 7 Week Squat Program Spreadsheet
Tim Swords 7 Week Squat Program Spreadsheet (alt)