For some reason or other I do not have the first volumes of either Madeleine L'Engle's Time series or Peter Dickinson's Changes Trilogy. I think this is because when we moved to this house 20+ years ago a box of books went missing in the move. I am gradually discovering what was in that box - a bit late I know, but I always wondered what it contained.
So you get incomplete series in this post.
Madeleine L'Engle is famous for her book A Wrinkle in Time a sort of time travel adventure. The sequels are A Swiftly Tilting Planet and A Wind in the Door. There were two other books, but I don't have them, but have an unrelated book, The Young Unicorns.
Peter Dickinson is another excellent children's and young adult book writer. His The Changes trilogy, SF set in a near-future England in which use of machines is equated with witchcraft. I have the second two books in the trilogy, though I'm certain I had Weathermonger at some stage.
He has written many books and I have several individual novels such The Dancing Bear, Blue Hawk and Tulku which won the Whitbread Prize and the Carnegie Medal 1979. Below are the covers.
Next - to wind up the children's fantasy section - a miscellaneous selection of old and unusual juveline fiction.