BS 7925-2 is the Software Component Testing Standard.
It may be ordered from BSI by following the link BS
7925-2 Software component testing
But, be warned - it is not cheap.
Alternatively, of the draft SIGIST Standard from which this official British Standard was produced are available - a zipped copy of the the draft BCS Software Component Testing Standard is available for download here, and is also available to view online.
Comments received on this standard may be viewed on the BS 7925-2 Comments page.