EDIT

In cichorieae (maybe also E+M) some reference records had a large number of similar extensions.
Most of them (in cich) have already been removed (but not in AUD).

To find all of them use the following sql (adapt Reference_id in second sql, and adapt type_id for other ex-types or in E+M)

SELECT MN.*, e.* 

FROM Reference_Extension MN INNER JOIN Extension e ON e.id = MN.extensions_id
WHERE MN.Reference_id IN (

SELECT id FROM (
SELECT r.id, r.titleCache,  e.value, e.type_id, COUNT(*) AS n
FROM Reference r INNER JOIN Reference_Extension MN ON MN.Reference_id = r.id INNER JOIN Extension e ON e.id = MN.extensions_id
GROUP BY r.id, r.titleCache, e.type_id, e.value
HAVING n > 2
ORDER BY r.titleCache, r.id DESC
) AS tmp)
-- AND MN.Reference_id = 4234
ORDER BY MN.Reference_id
;


SELECT e.id
FROM Reference_Extension MN INNER JOIN Extension e ON e.id = MN.extensions_id
WHERE MN.Reference_id = 10911 AND e.type_id IN (2075, 2076)

For removal use something like

SELECT *
FROM Extension e
WHERE e.id IN (  44536 , 44537, ...)
;

SELECT *
FROM Reference_Extension MN
WHERE MN.extensions_id IN ( 44536 , 44537, ... )

which can be filled by results from above second sql