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