Note 6 - Share Based Compensation - Expenses for Continuing Operations (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based compensation expense	$ 54,230	$ 137,101	$ 709,788	$ 794,189
Selling, General and Administrative Expenses [Member]
Share-based compensation expense	51,157	121,999	632,793	690,612
Research and Development Expense [Member]
Share-based compensation expense	$ 3,073	$ 15,102	$ 76,995	$ 103,577

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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