Note 2 - Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Accounts receivable	$ 223,116		$ 226,104
Less: allowance for doubtful accounts	(4,662)	$ (4,662)	(7,315)
Net accounts receivable	$ 218,454		$ 218,789