Note 2 - Summary of Significant Accounting Policies (Tables)

6 Months Ended

Dec. 31, 2017

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three M onths E nded December 3 1 , 2017				Three M onths E nded December 3 1 , 201 6
	Revenue				Revenue
Fund
USO	$	2,499,615	52	%	$	3,683,953	57	%
USCI		979,375	20	%		1,323,374	20	%
UNG		874,162	18	%		894,996	14	%
All Others		492,472	10	%		570,208	9	%
Total	$	4,845,624	100	%	$	6,472,531	100	%

	Six M onths E nded December 3 1 , 2017				Six M onths E nded December 3 1 , 201 6
	Revenue				Revenue
Fund
USO	$	5,443,460	54	%	$	7,303,214	57	%
USCI		1,957,993	20	%		2,696,650	21	%
UNG		1,572,018	16	%		1,718,109	13	%
All Others		1,030,101	10	%		1,122,502	9	%
Total	$	10,003,572	100	%	$	12,840,475	100	%

	December 31, 2017				June 30, 2017
	Accounts Receivable				Accounts Receivable
Fund
USO	$	799,623	50	%	$	1,060,421	60	%
USCI		326,005	20	%		317,032	18	%
UNG		312,466	20	%		217,760	12	%
All Others		164,334	10	%		167,058	10	%
Total	$	1,602,428	100	%	$	1,762,271	100	%

Property, Plant and Equipment, Estimated Useful Life [Table Text Block]

Category	Estimated Useful Life (in years)
Plant and equipment:		5	to	10
Furniture and office equipment:		3	to	5
Vehicles		3	to	5