Note 4 - Accounts Receivable - Accounts Receivable (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Accounts receivable	$ 2,127,934	$ 2,446,486
Expected credit losses	(53,821)	(53,708)
Net accounts receivable	$ 2,074,113	$ 2,392,778