CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Dec. 31, 2018	Jun. 30, 2018
Allowance for doubtful accounts on trade receivables (in dollars)	$ 13,989	$ 13,389
Common stock, par value (in dollars per share)	$ 1	$ 1
Prior Cumulative Preferred Stock, $5 Par Value: | Series A
Preferred stock, par value (in dollars per share)	$ 5	$ 5
Preferred stock, liquidation preference (in dollars)	$ 2,325,000	$ 2,310,000
Prior Cumulative Preferred Stock, $5 Par Value: | Series B
Preferred stock, par value (in dollars per share)	$ 5	$ 5
Preferred stock, liquidation preference (in dollars)	$ 2,280,000	$ 2,265,000
Cumulative Preferred Stock, $20 Par Value: | Series A
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, liquidation preference (in dollars)	$ 5,224,063	$ 5,194,796
Cumulative Preferred Stock, $20 Par Value: | Series B
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, liquidation preference (in dollars)	$ 851,363	$ 846,594