I'm currently looking for a Clementi piece. I have a recording of it Maria Tipo, Luciano Di Labio and Giannino Ferrari. In the booklet of the CD, it's listed as "12 Waltzes for the pianoforte, triangle and tambourine, Op. 38" :

However, on IMSLP, when I looked at the page http://imslp.org/wiki/List_of_works_by_Muzio_Clementi, it shows op.38 as piano sonatinas.
Where can I find these waltzes for piano, triangle and tambourine ? Are they still copyrighted ?
Thanks in advance.