Note 8 - Equity - Earnings Per Share (Details) - USD ($)	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Basic earnings (loss) per share
Net loss	$ (409,223)	$ (1,126,523)
Preferred stock dividends	(85,715)	(84,550)
Net loss available to common shareholders after preferred stock dividends	$ (494,938)	$ (1,211,073)
Weighted average shares used in the computation of basic earnings per share (in shares)	7,365,723	7,249,370
Loss per share - basic (in dollars per share)	$ (0.07)	$ (0.17)
Dilutive earnings (loss) per share
Loss available to common shareholders	$ (494,938)	$ (1,211,073)
Weighed average shares used in the computation of diluted loss per share (in shares)	7,365,723	7,249,370
Shares used in the computation of diluted loss per share (in shares)	7,365,723	7,249,370
Loss per share - diluted (in dollars per share)	$ (0.07)	$ (0.17)