Note 4 - Accounts Receivable - Accounts Receivable (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Accounts receivable	$ 2,134,389	$ 2,446,486
Expected credit losses	(52,912)	(53,708)
Net accounts receivable	$ 2,081,477	$ 2,392,778