Building a Corpus of Facial Expressions for Learning-Centered Emotions. - María Lucía Barrón-Estrada; Ramón Zataraín-Cabada; Bianca Giovanna Aispuro-Medina; Elvia Minerva Valencia-Rodríguez; Ana Cecilia Lara-Barrera (Res. Comput. Sci., 2016)