Man pages matching name whirlpoolsum in section 1p:

whirlpoolsum.1p.en	debian 10 / libdigest-whirlpool-perl
whirlpoolsum.1p.en	debian 11 / libdigest-whirlpool-perl
whirlpoolsum.1p.en	debian 12 / libdigest-whirlpool-perl