Normalize duplicate text

In a field (e.g. PUBLISHER) I often find information that is stored there two times.
For example "2021 The Numero Group 2021 The Numero Group".
How can I remove the redundancy from these strings?

Is it really the string

or does it look like
2021 The Numero Group\\2021 The Numero Group

It's really the string as postet, no delimiter in this.

If the separator is the number, then this would work:
$regexp('2021 The Numero Group 2021 The Numero Group',(.*) (\d+.*),$1)

Thank you, good idea to solve this issue. :hugs:
But how to handle
"(C) 2013 AP Music Ltd (P) 2013 AP Music Ltd"

According to my test
$regexp('(C) 2013 AP Music Ltd (P) 2013 AP Music Ltd',(.*) (\d+ .*),$1)
leads to
"(C) 2013 AP Music Ltd (P)"
and as (C) and (P) are not really duplicates ...

TBH: in this case you do not have the number as separator but a single letter in brackets. So use that.