Please add Series number

[Halcyon]

Concerns:

ISBN 9789044855883
Author: Jeroen van Berckum
Title: Elmwood

This title is book 3 in a series called De schaduwkronieken. The other two books are:

* ISBN 9789044843620
Author: Jeroen van Berckum
Title: Villa Vita Nova
Serie: De schaduwkronieken #1

* ISBN 9789044849103
Author: Jeroen van Berckum
Title: De Laatste Vijf
Serie: De schaduwkronieken #2

Thank you for linking them together!

[Emmy]

To be a series on Goodreads, books need to have more than a common theme -- like characters in common, an overarching storyline, a shared universe, etc. What makes this a series?

(Links to the books in question would be helpful).