I'm using external sources to get the information I need

I think a bit of wordplay and inference is acceptable, though.
Speaking of citation, though, I can't find enough reference-able material for the question on the advantages of early birth (6b?)
(Also here's my answer for 6a if it helps any)
6a
Newborn marsupials, while generally at an early stage of development due to the exceedingly short gestation period of their mothers, have comparatively well-developed forelimbs, in contrast to other parts of their anatomy, such as their permanently shut eyes and primordial hind limbs (Ladiges, Gleadow & Handasyde 2013). The well-developed forelimbs and claws, in combination with a sturdy chest and heart, are significant as they allow the largely helpless neonate to pull itself up from the vaginal opening to the pouch and teat of its mother with negligible assistance (the mother may lick the pathway to her pouch to reduce the desiccation and improve the grip of her young, but gives no further help to her offspring) (Ladiges, Gleadow & Handasyde 2013; Nature of Australia: A separate creation 1988).