hack//SIGN ORIGINAL SOUND & SONG TRACK1 - Album by Yuki Kajiura

hack//Sign - Wikipedia

Watch Order of the .Hack series – All About Anime and Manga

Sora (.hack//sign) - Zerochan Anime Image Board

Funimation Entertainment License Rescue a Number of .hack// Anime Series

.hack//Legend of the Twilight: Anime Legends Complete Collection [DVD] : Steve Blum, Junko Minagawa, Mai Nakahara, Yuki Matsuoka, Yuki Kaida, Ayako Kawasumi, Maaya Sakamoto, Yasunori Masutani, Nobuyuki Hiyama, Soichiro Hoshi, Sakiko

SIGN op/ed, .hack//Wiki

hack//Sign - Anime Legends Complete Collection

hack//Sign Episode 1

The best gaming anime of all time is .hack//SIGN, and it's now streaming - Polygon

The 18-Year-Old Anime That's Still Ahead Of It's Time, by Eric Mueller