Note 9 - Major Customer and Vendor (Details)	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Number Of Major Distributors	The Company sold products through ten distributors	The Company sold products through ten distributors
Concentration Risk, Other Risk	Sales to four distributors represented 19%, 16%, 11% and 11% of total sales
Concentration Risk, Product	Sales of four products represented 37%, 17%, 11%, and 11% of total sales	Sales of three products represented 53%, 15%, and 14% of total sales
ShandongYctMember
Concentration Risk, Supplier	54%	33%
OtherVendor1Member
Concentration Risk, Supplier	19%	23%
OtherVendor2Member
Concentration Risk, Supplier	14%	18%
OtherVendor3Member
Concentration Risk, Supplier		14%