XML 39 R27.htm IDEA: XBRL DOCUMENT v3.21.2
Note 2 - Accounts Receivable - Allowance for Doubtful Accounts (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Accounts receivable allowance, beginning of period $ 77,623 $ 42,623
Provision adjustment 0 64,378
Write-off 0 (29,378)
Accounts receivable allowance, end of period $ 77,623 $ 77,623