Note 3 - Accounts Receivable, Net (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

	As of			As of
	September 30, 2019			December 31, 2018
Accounts receivable	$	13,666,124		$	15,064,580
Less: allowance for doubtful accounts		(576,349	)		(658,104	)
Accounts receivable, net	$	13,089,775		$	14,406,476

Financing Receivable, Allowance for Credit Loss [Table Text Block]

	For the Nine Months Ended
	September 30, 2019			September 30, 2018
Beginning balance	$	658,104		$	567,108
Provision (reversal) for doubtful accounts		(50,090	)		89,019
Less: write off/recovery		(31,665	)		(26,788	)
Ending balance	$	576,349		$	629,339