Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Accumulated depreciation	$ 2,178,483	$ 2,058,483
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	100,000	100,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	23,489,711	23,395,211
Common stock, shares outstanding (in shares)	23,424,699	23,319,287
Treasury stock, shares (in shares)	65,012	75,924

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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