I have found 2; one for orc and one for dunmer. I haven't read them yet because I'm not sure if I will keep these characters when I transfer to console. Are the motifs like recipes and good only for the character who reads them? Have motifs become more available after recent patches? I really haven't been too far afield yet and I think both that I have were found near the bank in Vulkhel Guard.
Scura di Notte - Altmer Nightblade (gear)
Lalin del Sombra - Bosmer Sorcerer (alchemy/enchanting)
Angevin Sarkany - Bosmer Dragonknight
Alkemene Velothi - Dunmer Warden (Morrowind)
Sanna yos'Phalen - Altmer Sorcerer (provisioning)
Cosima di Mattina -Altmer Sorcerer
Naria Andrano - Dunmer Templar
Luca della Serata - Redguard Templar