Good resources about understanding grief

I gave a talk last night in which I said that one part of supporting families living with ASD is being sensitive to grief and understanding what people experience when they are grieving. At the end I took questions and was asked if I could recommend some resources about grief. Of course I couldn't there on the spot and I felt a leetle bit embarrassed, but I've come up with some here. 

How People Grow by Cloud and Townsend is an old book now but it's still a goody. It has some wonderful words about grief, support and needing other people to mourn with. I recommend it for general life as well!

Jerry Sittsers books about grief and loss are written out of deep experience. He lost his wife and daugher in a car accident and writes so beautifully and honestly about his soul and what he's learned and lived.

Elizabeth Kubler Ross did the original research on the five stages of grief. Although I haven't read her book, I imagine it would be considered a classic.

And then of course there's CS Lewis with A Grief Observed, written after the death of his wife.

I've also appreciated Philip Yancy's books about Pain - not just this one but also 'The Gift of Pain'.