Note 6 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2020	Mar. 31, 2019
Paid time off accrual	$ 55,240	$ 55,900
Inventory reserve	45,948	41,572
Depreciation and amortization	22,651	112,125
Stock-based compensation deductions	65,218	62,671
Unrealized (gain) loss on marketable securities	(144,668)
Unrealized (gain) loss on marketable securities		23,170
Other	63,730	58,297
Deferred tax assets	$ 108,119	$ 353,735

Deferred Tax Assets, Depreciation

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from inventory.

+ References

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-Publisher FASB
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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from employee benefits, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from unrealized losses on available-for-sale securities.

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Amount of deferred tax liability attributable to taxable temporary differences from unrealized gains on trading securities.

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