Aragones, L., & Palencia, R. (2014a). McGraw-Hill Education Beginning Spanish Grammar. McGraw-Hill Education - Europe.
Aragones, L., & Palencia, R. (2014b). McGraw-Hill Education Beginning Spanish Grammar. McGraw-Hill Education - Europe.
Aragones, L., & Palencia, R. (2014c). McGraw-Hill Education Intermediate Spanish Grammar. McGraw-Hill Education - Europe.
Aragones, L., & Palencia, R. (2014d). McGraw-Hill Education Intermediate Spanish Grammar. McGraw-Hill Education - Europe.
Collins Spanish Dictionary & Grammar (8th Edition). (2018). HarperCollins Publishers.
Galimberti Jarman, B., Russell, R., Carvajal, C. S., & Rollin, N. (2008). The Oxford Spanish Dictionary: Spanish-English, English-Spanish (4th Edition). Oxford University Press Inc.
Nissenberg, G. (2016). Complete Spanish Grammar (3rd Edition). McGraw-Hill Education.
Pinilla, R., & San Mateo, A. (2016a). El Expres: Exercises Book Levels A1, A2, B1: Curso Intensivo de Espanol. SGEL.
Pinilla, R., & San Mateo, A. (2016b). ELExprés: Curso Intensivo De Español. SGEL.
Richmond, D. D. (2015). Spanish Verb Tenses (3rd Edition). McGraw Hill Education.
Six, A. L. (2001a). Upgrade Your Spanish. Arnold.
Six, A. L. (2001b). Upgrade Your Spanish. Arnold. https://ebookcentral.proquest.com/lib/rhul/detail.action?docID=581413