t´as l´air trop fainéant pour chercher alors 
source : Gamefaqs
Taymiya: Talk to Quzman´s wife after getting the Family Tree. ( 1)
Usaybia: Later in the game, when you can return to Pherkad, examine
the portrait of Quzman´s dead ex-wife, he will sign for her. ( 2)
Hawqal: In Moonguile Forest, help the man catch the Bluebirds of
Happiness ( the area before the Lord of The Springs). ( 3)
Surayj: In Cebalrai, talk to the woman in the stable with the Pows
and she will sign. ( 4)
Rushd: In Pherkad, in the Area with the shop and blue flower, talk
to the little girl sitting on the fence near the port and give her
a dead Bluebird to make her sign the Family Tree. ( 5)
Sabin: Once Rushd sign, talk to her father Sabin next to her
to make him sign too. If Nubata ( Mira island) has already signed,
you´ll need to give him the Naughty Novel to make him sign. The
Naughty Novel can be found in Quzman´s bedside table. ( 6)
Sallam: After making Rushd and Sabin sign the Family Tree, talk to
Sabin´s son ( the brat running around near them). ( 7)
Al-athir: In the Lord´s Mansion in Pherkad, talk to the girl in the
kitchen and give her Pow Milk Cheese to make her sign. To get Pow
Chesse, get some Pow Milk and let it sit for a long time. ( 8)
Maymun: In Nashira, talk to the woman on the second floor of the
warehouse where they keep the fish. ( 9)
Rustah: In Lesser Celestial River, go past the area where the
Thunderfish was and continue until you see a drowning kid in
the river and save him. ( 10)
Hisham: After saving Rustah, go on the other side of the river
and look at the end of the river to see Rustah´s brother. Save
him make him sign. ( 11)
Qutayba: In Cloud Passage, where it was flooded, talk to the father
of the two drowning kids after saving them and show him the Family
Tree to make him sign. ( 12)
Tufayr: Defeat the boss _____ in the Ancient Library of Magic,
then go back in the Philosophy room and a man will be there. ( 13)
Tulun: In the School of Magic ( right section), after Tufayr signed
the Family Tree, talk to his sister. She´s in the first room,
looking at the wall. ( 14)
Nubata: In Parnasse Village, talk to the fat man lying down at the
entrance. If Sabin ( Salaad Sud island) has already signed, you will
need to give him a Roasted Bird to make him sign ( cooked Bluebird
of Hapiness in Trill´s oven). ( 15)
Misjah: In Reverence, talk to the old woman ( Quzman´s ex-wife) near
the bridge and give her the Terrible Painting ( found in Quzman´s
house, in his dresser). ( 16)
Qasim: In Mintaka, near the first house across the port, talk to
the man in black. ( 17)
Yamin: In Cursa, talk to the woman next to the shop and show her the
Family Tree. She will only sign it if Usaybia already signed. ( 18)
Yunus: Go to the Ice Cliffs of Gomeisa and talk to the father
looking for his daughter. To find the daughter, go down the slope
to the next area, then up the slope at the right and go left. ( 19)
Yamin must sign before her.
Gabirol: After saving Yunus ( his daughter), go back to talk to him
and he will sign it. ( 20)
Bajja: After Yamin, Yunus and Gabirol have signed the family tree,
go back to Quzman´s house and talk to Yamin there and she will
sign for Bajja. ( 21)
Battuta: In the Labyrinth of Duhr, it´s the man in a dead-end. ( 22)
Wahshiyah: In Gemma Village, talk to the old woman near the
entrance. ( 23)
Al-khatib: In Celestial Alps, after defeating the bosses, go back to
the entrance and you´ll see a woman with a red dress. Talk to the
woman and the daughter, and after a few times the daugher will
ask you to push her up. Only after that will she sign. ( 24)
Al-rumi: She will sign once you pushed her lazy daughter up the
cliff. ( 25)
Tumart: In the Illusory Fortress of the Book, in the second room, go
through the second door on the right wall, there will be a mna. Save
him, and he will sign. ( 26)
Kemal: After Tumart has signed the Family Tree, go to Quzman´s house
and talk to Tumart and he will sign for Kemal. ( 27)
Zhur: In Nihal Desert, go west three times from the entrance to find
a woman buried in the sand. Help her and give her Pristine Water. ( 28)
Asakir: Once Zhur has signed the Family Tree, go back to Nunki Valley
and talk to the man standing under the waterfall working out. ( 29)
Maja: After Asakir has signed the Family Tree, go back to Quzman´s house
and talk to Asakir and he will sign for Maja. ( 30)
Rabbih: He is on the fourth floor of the Zosma Tower. He will sign if you
bring him a Delinquency Stone, Which is on the first floor of the tower´s
basement. He will only sign last. ( 31)
, ne me donner pas la solution de " kuja_le_rebelle" 
j´suis tous seul 
Je les ai tous trouvés avec ca