broken reference to fieldstone

[tjhei]

See https://github.com/geodynamics/aspect/blob/5e8b80b578b8b2b50955642eacca6765b76e3779/doc/sphinx/references.bib#L11841C1-L11846C2

but the pdf no longer exists.

@cedrict ?

[gassmoeller]

I think a new version is available at https://surfdrive.surf.nl/files/index.php/s/3FzywhtK0DgAtQA, but inside it @cedrict asks for Fieldstone to be cited as:

@article{fieldstone,
author = "Cedric Thieulot",
title = "{Fieldstone: a computational geodynamics (self-)teaching tool}",
year = "2023",
doi = "10.5194/egusphere-egu23-14212"}

We should probably use that bib entry (including doi).

[cedrict]

I am fine if you only use my website address https://cedrict.github.io/