Note 5 - Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accounts receivable - current	$ 1,411,462		$ 1,411,462		$ 561,834
Loss on foreign currency transactions	(50,000)	$ 0	(50,000)	$ 0	0
Allowance for doubtful account	(13,785)		(13,785)		(13,785)
Accounts receivable, net of allowances for doubtful accounts	$ 1,347,677		$ 1,347,677		$ 548,049