import re
rx = re.compile(r"\(([^()\d]*\d[^()]*)\)")
s = "Some (Author) and (Author 2000) and (another author 2019)"
print(rx.findall(s))
aW1wb3J0IHJlCgpyeCA9IHJlLmNvbXBpbGUociJcKChbXigpXGRdKlxkW14oKV0qKVwpIikKcyA9ICJTb21lIChBdXRob3IpIGFuZCAoQXV0aG9yIDIwMDApIGFuZCAoYW5vdGhlciBhdXRob3IgMjAxOSkiCnByaW50KHJ4LmZpbmRhbGwocykpCg==