[1]
Aragones, L. and Palencia, R. 2014. McGraw-Hill Education Beginning Spanish Grammar. McGraw-Hill Education - Europe.
[2]
Aragones, L. and Palencia, R. 2014. McGraw-Hill Education Beginning Spanish Grammar. McGraw-Hill Education - Europe.
[3]
Aragones, L. and Palencia, R. 2014. McGraw-Hill Education Intermediate Spanish Grammar. McGraw-Hill Education - Europe.
[4]
Aragones, L. and Palencia, R. 2014. McGraw-Hill Education Intermediate Spanish Grammar. McGraw-Hill Education - Europe.
[5]
Galimberti Jarman, B. et al. 2008. The Oxford Spanish Dictionary: Spanish-English, English-Spanish. Oxford University Press Inc.
[6]
Nissenberg, G. 2016. Complete Spanish Grammar. McGraw-Hill Education.
[7]
Pinilla, R. and San Mateo, A. 2016. El Expres: Exercises Book Levels A1, A2, B1: Curso Intensivo de Espanol. SGEL.
[8]
Pinilla, R. and San Mateo, A. 2016. ELExprés: Curso Intensivo De Español. SGEL.
[9]
Richmond, D.D. 2015. Spanish Verb Tenses. McGraw Hill Education.
[10]
Six, A.L. 2001. Upgrade Your Spanish. Arnold.
[11]
Six, A.L. 2001. Upgrade Your Spanish. Arnold.
[12]
2018. Collins Spanish Dictionary & Grammar. HarperCollins Publishers.