Note 4 - Inventories - Summary of Inventories (Details) - USD ($)	Mar. 31, 2020	Mar. 31, 2019
Raw materials	$ 1,017,451	$ 1,130,917
Work in process	1,863,000	2,325,238
Finished goods	1,003,999	808,721
Total inventories	$ 3,884,450	$ 4,264,876	[1]

[1] The March 31, 2019 Balance Sheet is derived from the audited financial statements contained in our Annual Report on Form 10-K for the fiscal year ended March 31, 2019.