Find all tables referencing a given table's primary key

show_constraints.sql

SELECT S.TABLE_NAME SOURCE,
  S.CONSTRAINT_NAME CONTRAINTE,
  T.TABLE_NAME CIBLE,
  T.CONSTRAINT_NAME PK
FROM USER_CONSTRAINTS S,
  USER_CONSTRAINTS T
WHERE T.TABLE_NAME      = '<target_table>'
AND T.CONSTRAINT_TYPE   = 'P'
AND S.R_CONSTRAINT_NAME = T.CONSTRAINT_NAME;
---
SELECT DISTINCT(S.TABLE_NAME) SOURCE,
  T.TABLE_NAME CIBLE,
  T.CONSTRAINT_NAME PK
FROM USER_CONSTRAINTS S,
  USER_CONSTRAINTS T
WHERE T.TABLE_NAME      = '<target_table>'
AND T.CONSTRAINT_TYPE   = 'P'
AND S.R_CONSTRAINT_NAME = T.CONSTRAINT_NAME
ORDER BY S.TABLE_NAME ASC;