Xuanxuan Qijing Problem 347
From LiChangHo Jingjiang Weiqi Shoujin 李昌镐精讲围棋手筋 Volume 5, page 59, Graded Go Problems for Beginners Volume 4, problem 115, page 24, and many other sources.
Also known as 五龙取水 (five dragons seeking water) and 龟势 (tortoise shape) in classical texts.