Steck-Vaughn School Supply. (2004). E S L building english proficiency. Steck-Vaughn Company.
Citazione stile Chigago Style (17a edizione)Steck-Vaughn School Supply. E S L Building English Proficiency. Nueva York: Steck-Vaughn Company, 2004.
Citatione MLA (9a ed.)Steck-Vaughn School Supply. E S L Building English Proficiency. Steck-Vaughn Company, 2004.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.