Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Aug. 31, 2021	Nov. 30, 2020
Allowance for doubtful accounts	$ 40,582	$ 51,175
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	500,000	500,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	9,500,000	9,500,000
Common stock, issued (in shares)	4,578,504	4,470,004
Treasury stock (in shares)	(44,532)	(35,097)

Amount of allowance for credit loss on accounts receivable, classified as current.

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