Consolidated Balance Sheets (Parentheticals) - USD ($)	Jun. 30, 2021	Jun. 30, 2020
Consolidated Balance Sheets [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 41,500	$ 74,082
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)	8,608,706	7,404,831
Common stock, shares outstanding (in shares)	8,608,706	7,404,831