URLs

• http://www.doujinshi.org/browse/author/380/Utatane-Hiroyuki/
• https://www.mangaupdates.com/authors.html?id=3536
• https://en.wikipedia.org/wiki/Hiroyuki_Utatane
• https://ja.wikipedia.org/wiki/うたたねひろゆき
• https://anidb.net/creator/10155
• https://www.animenewsnetwork.com/encyclopedia/people.php?id=7169
• http://www.artjeuness.net/artist/utatane/