Consolidated Balance Sheets (Parentheticals) - USD ($)	Jun. 30, 2019	Jun. 30, 2018
Accounts receivable, allowance for doubtful accounts	$ 2,617	$ 55,872	[1]
Common stock, par value (in dollars per share)	$ 0.005	$ 0.005
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	7,404,831	7,382,706
Common stock, shares outstanding (in shares)	7,404,831	7,382,706

[1] As adjusted for the retrospective adoption of ASC 606 and ASC 842