Note 9 - Concentrations (Details Textual)	12 Months Ended
Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Revenue from Contract with Customer, Including Assessed Tax	$ 3,485,992	$ 3,018,954
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| One Customer [Member]
Concentration Risk, Number of Customers	1
Concentration Risk, Percentage	48.00%
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Two Customers [Member]
Concentration Risk, Number of Customers		2
Concentration Risk, Percentage		58.00%
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Foreign Customers [Member]
Concentration Risk, Percentage	9.00%	12.00%
Revenue from Contract with Customer, Including Assessed Tax	$ 324,596	$ 364,418
Customer Concentration Risk [Member] \| Accounts Receivable [Member] \| Two Customers [Member]
Concentration Risk, Number of Customers		2
Concentration Risk, Percentage		88.00%
Customer Concentration Risk [Member] \| Accounts Receivable [Member] \| Three Customers [Member]
Concentration Risk, Number of Customers	3
Concentration Risk, Percentage	83.00%

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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