CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($)	Jun. 30, 2020	Jun. 30, 2019
Allowance for doubtful accounts on trade receivables (in dollars)	$ 13,171	$ 12,849
Common stock, par value (in dollars per share)	$ 1	$ 1
Prior Cumulative Preferred Stock
Preferred stock, par value (in dollars per share)	$ 5	$ 5
Prior Cumulative Preferred Stock - Series A
Preferred stock, liquidation preference (in dollars)	$ 2,370,000	$ 2,340,000
Prior Cumulative Preferred Stock - Series B
Preferred stock, liquidation preference (in dollars)	$ 2,325,000	$ 2,295,000
Convertible Cumulative Preferred
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Cumulative Preferred Stock - Series A
Preferred stock, liquidation preference (in dollars)	$ 5,311,862	$ 5,253,329
Cumulative Preferred Stock - Series B
Preferred stock, liquidation preference (in dollars)	$ 865,672	$ 856,133