XML 42 R31.htm IDEA: XBRL DOCUMENT v3.21.2
Note 1 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2021
Dec. 31, 2020
Allowance for doubtful accounts $ 498,044 $ 612,434
Bad debt expense 76,280 320,270
Receivables written off during the periods (24,895) (484,265)
Effect of currency translation (16,607) 49,605
Allowance for doubtful accounts $ 532,822 $ 498,044