Statements of Cash Flows - USD ($)	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Operating activities
Royalties received	$ 449,496	$ 3,149,582
Interest received	37,314	40,324
Expenses paid	(529,257)	(817,592)
Net cash from (used for) operating activities	(42,447)	2,372,314
Investing activities
Maturities of U.S. Government securities	26,899,691	18,236,603
Purchases of U.S. Government securities	(13,567,217)	(2,803,492)
Net cash from investing activities	13,332,474	15,433,111
Financing activity
Distributions to unitholders	(9,184,007)	(18,236,814)
Net change in cash and cash equivalents	4,106,020	(431,389)
Cash and cash equivalents, beginning of period	10,177,655	881,810
Cash and cash equivalents, end of period	14,283,675	450,421
Reconciliation of net income to net cash from operating activities
Net income	1,611,621	4,910,288
Decrease (increase) in accrued income receivable	38,605	(1,038,520)
Increase in contract asset		(1,238,447)
Increase in prepaid expense	(11,197)	(16,613)
Increase (decrease) in accrued expenses	39,082	(244,394)
Decrease in contract liability	(1,720,558)
Net cash from (used for) operating activities	(42,447)	2,372,314
Non cash financing activity
Distributions declared and payable	$ 7,347,206	$ 12,332,809