Free public domain sheet music from IMSLP / Petrucci Music Library
Berlin & Amsterdam: J. J. Hummel, n.d. (1776), Plate 499.
Public Domain [tag/del]
The 'I' on the opus number (of the title-page of Quartets 1-3) has been penned in, so that it appears to be Op.9 (IX); these are in fact both halves of Op.10, as the individual Quartet numbering shows, and they have the same Plate Number.
||6 Quartets for Flute and Strings, Op.10
||Quatuors a Flute, Violon, Alto & Violoncelle oblige
||6 quartets of 3 movements each
||1776 (according to Grove)
||Flute, violin, viola, cello