Pal Negyesi
Journalist and Hungarian marque specialist.
Pal Negyesi

Fortepan
Fortepan is an online photo archive. In early 2018 there were over 96,000 images available, all under Creative Commons CC-BY-SA-3.0 licence.
fortepan.hu

Danuvia and D-Csepel
Extensive information on these machines.
Danuvia 125 and D-Csepel