Oxford Music Online (subscription access), accessed 29 January 2012.

This service allows subscription access to Hitwise's reports.

L. Macy (accessed 16 January 2005), grovemusic.com (subscription access).

A randomised trial found an increase in content downloads of open access papers, with no citation advantage over subscription access one year after publication.

L. Macy (accessed 30 January 2006), grovemusic.com (subscription access).

Contemporary Music Review 26, issues 3 & 4 (subscription access).

Online link accessed 19 November 2007 (subscription access).

L. Macy (accessed 7 May 2006), grovemusic.com (subscription access).

In addition to the free version, subscription access is also offered.

That could open the door for more companies to offer subscription access to specialized software services via iOS apps.