Bayona (2009) also notes that the factors that most facilitate L3 learning are: typological similarity to previously acquired languages (L1 or L2), proficiency in the L2, and recency (how recently the L2 has been activated).
the result that some learners transferred more from their L1 and more from their L2 is congruent with L3 acquisition studies such as Chin (2009) and Jin (2009) that suggest that L3 learners will transfer from either their L2 or L1, depending on proficiency in the language, recency, and typological similarity.