이외에도 입양이나 후원을 통해 가족이 되는 경우도 있다. (이외에도 -> 이 외에도) => Apart from these, there are cases where they join the family through adoption or sponsorship. * 이외에 and 이외에도 (도 adds the sense of "as well") are set phrases for "besides X" or "in addition to X", but they usually require a noun before it, as in 이같은 사례 이외에도 ... (Besides these examples, ...). In your example, it comes in the beginning of the sentence, so I think it should be 이 외에도 (besides this/these), a similar but separate expression. This phrase is like 이것(들) 외에도 = 이 외에도 = 이밖에도 (you could also use 그 외에도, 그밖에도, etc. in the same way). These are complete in themselves because 이(this) and 그(that) functions as the group or realm that 외 or 밖 is in reference to. 외 and 밖 mean "outside". 후원 (후 = rear, after, 원 = support, assistance) means a support, backing, or sponsorship. 후원하다 is the verb.