Note 5 - Plant, Property, and Equipment, Net: Property, Plant and Equipment (Details) - USD ($)	Dec. 31, 2018	Mar. 31, 2018
Property, Plant and Equipment, Gross	$ 20,439,902	$ 22,211,740
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(5,947,625)	(5,418,327)
Plant, property, and equipment, net	14,492,277	16,793,413
Other Machinery and Equipment
Property, Plant and Equipment, Gross	3,316,669	3,594,861
Office Equipment
Property, Plant and Equipment, Gross	771,453	769,589
Building
Property, Plant and Equipment, Gross	12,466,550	13,606,722
Leasehold Improvements
Property, Plant and Equipment, Gross	$ 3,885,230	$ 4,240,568