Note 12 - Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2020	Mar. 31, 2019
Net operating loss carry-forward	$ 536,000	$ 637,000
Research & development tax credit carry-forward	429,000	429,000
Other	54,000	41,000
Deferred tax asset, net	$ 1,019,000	$ 1,107,000