Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Feb. 28, 2021	Nov. 30, 2020
Allowance for doubtful accounts	$ 25,974	$ 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)	4,563,504	4,470,004
Treasury stock (in shares)	40,667	35,097