What to do when #Wikipedia does not provide the information

King Abd al-Rahman of #Morocco was a nephew of the king that preceded him. His father of mother were probably brothers of king Slimane. As long as I do not know exactly how they are related, the genealogy tool made by Magnus will not show all the rulers of the Alaouite dynasty.

Wikipedia does not have this information.

• I googled
• I went to the library
• I asked on Facebook in a SIG with many people from Morocco

So far I do not have my answer. I am really curious what the best way is for finding answers to a question like this one.

Thanks,

        GerardM