An interesting paper on the topic is The influence of bilingualism on third language acquisition: Focus on multilingualism (2013) published in Language Teaching 46(1):1 - 16 (2013) by Jasone Cenoz. She has published extensively on the topic so you can find her research through ResearchGate or Google scholar.
Many interesting articles related to this issue might be found in some journals, e.g. International Journal of Bilingualism, Bilingualism: Language and Cognition, etc.