Sibley's page also claims these are opus 24, I think? (Is there an easy to access source for the Trimpert/T numbers anyway? One of the better online lists for Cambini's works I seem to be able to find, at wikipedia:nl:Giuseppe Maria Cambini, only lists opus numbers, apparently... Eric 21:29, 13 August 2010 (UTC)
Matters are a bit more complicated here: This Quartet was counted as the 24th Quartet opus of Cambini; but this number is to be distinguished from the normal Opus numbers, which counted all published works by Cambini, no matter in which genre (in this list, Op.24 are 6 String Quartets, T.85-90). Even more confusing is the fact, that there exists also a second 24th book of Quartets consisting of String Quartets, T.151-156 (probably the publisher of one of these works was not aware of the edition of the other work and so chose the same Opus number: Publishers normally just looked what was the Opus number of the latest work that had appeared; this is probably the reason why opus numbers were sometimes added only by pen, obviously in the last moment). As far as I know, the only way to identify Cambini's quartets for sure, is looking into Trimpert's book, which is, however, not so easy to find even in libraries. But see now also the List of compositions by Giuseppe Maria Cambini Cgo
