Especially German forumists may be interested in Ian Youngs detailed article 'Zwiebelpflanzen aus Samen anziehen' (raising bulbous plants from seeds)
in Gartenpraxis 03-2020 - Verlag Eugen Ulmer, Stuttgart.
This is a fine summary of what was written on this subject in the 'Bulb Log', well illustrated and it is really a joy to read.
Gerd
