Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Accumulated Depreciation, Depletion and Amortization	$ 3,779,643	$ 3,745,861
Preferred Stock, Par or Stated Value Per Share	$ 0.03	$ 0.03
Preferred Stock, Shares Authorized	333,306	333,306
Preferred Stock, Shares Issued, Total	0	0
Preferred Stock, Shares Outstanding, Ending Balance	0	0
Common stock, par value (in dollars per share)	$ 0.03	$ 0.03
Common stock, shares authorized (in shares)	3,333,334	3,333,334
Common stock, shares issued (in shares)	1,028,863	1,028,863
Common stock, shares outstanding (in shares)	1,028,863	1,028,863