Note 5 - Restricted Cash - Restricted Cash (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jan. 31, 2020	Jul. 31, 2018
Restricted cash, beginning of period	$ 1,821,392	$ 1,789,899
Interest received	13,354	31,493
Restricted cash, end of period	$ 1,834,746	$ 1,821,392