I don’t know what kind of “authoritative” source you want, as clappers during the Triduum are entrenched in tradition. A quick search shows that they were used long before:Do you happen to know of an authoritative reference for this? I would like to read up on this. I know in some locations it is customary to very solemnly (not joyfully) toll the bells at 3:00 on Good Friday.
sanctamissa.org/en/sacristy/handbook-for-sacristan/handbook-for-sacristan-50.html
The 1921 “The Office of Holy Week” by Mazellini also indicates the use of clappers.
I think the modern Missal prescribes the bells to be silent. I don’t know what the older Missals commanded in addition to that.