Condensed Statements of Income (USD $)	3 Months Ended
	Apr. 30, 2013	Apr. 30, 2012
Revenues
Royalty income	$ 2,528,417	$ 3,693,121
Interest income	390	325
Total revenues	2,528,807	3,693,446
Expenses	326,418	323,554
Net income	$ 2,202,389	$ 3,369,892
Number of units outstanding	13,120,010	13,120,010
Net income per unit (Note 2) (in dollars per unit)	$ 0.1679	$ 0.2569
Distributions declared per unit (Note 3) (in dollars per unit)	$ 0.0800	$ 0.0650