Condensed Statements of Income - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Revenues
Royalty income	$ 2,619,097	$ 11,780,502	$ 6,667,942	$ 20,139,905
Interest income	2,468	2,256	6,993	6,647
Total revenues	2,621,565	11,782,758	6,674,935	20,146,552
Expenses	219,498	243,152	848,958	1,053,187
Net income	$ 2,402,067	$ 11,539,606	$ 5,825,977	$ 19,093,365
Number of units outstanding	13,120,010	13,120,010	13,120,010	13,120,010
Net income per unit (Note 2)	$ 0.1831	$ 0.8795	$ 0.4441	$ 1.4553
Distributions declared per unit (Note 3) (in dollars per unit)		$ 0.8800	$ 0.0400	$ 1.2000