Note 3 - Accounts Receivable, Net (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

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

	As of			As of
	June 30, 2019			December 31, 2018
Accounts receivable	$	14,251,593		$	15,064,580
Less: allowance for doubtful accounts		(563,768	)		(658,104	)
Accounts receivable, net	$	13,687,825		$	14,406,476

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

	For the Six Months Ended
	June 30, 2019			June 30, 2018
Beginning balance	$	658,104		$	567,108
Provision for doubtful accounts		(73,187	)		55,531
Less: write off/recovery		(21,149	)		(12,722	)
Ending balance	$	563,768		$	609,917