Trying to figure out a credits dispute with the song 2 Times. The back of the CD single for Ann Lee's recording of it credits Daniela Galli, Alfredo Pignagnoli, Ann Lee (Annerley Gordon) and Paul Sears as the writers. However, SIAE (and therefore also ISWC-Net) also lists Marco Sancini as an author, while the CD single only lists him as a producer. ASCAP, GEMA and JASRAC agree with the CD single.
I added Sancini as an author after Mark_Heyrman filed an error report, but because it's late here I didn't think to further research the situation until I was going to edit the external links to handle the data mismatch and noticed that I initially added GEMA as an external link (because it was covered in German by Die Schlümpfe I correctly assumed it would be listed there).
Do I keep Sancini as an author, or do I keep the credits the way they were and leave a note/mismatch for ISWC?