I found an article this morning when doing the study I promised titled "Democracy's Road to Tyranny" (https://fee.org/articles/democracys-road-to-tyranny/).  I've not heard of the site, the Foundation for Economic Education but it appears to be of a more conservative bent.  
I'm not sure that democracy and totalitarianism are the two ends of a continuum; I would think anarchy on the one side and absolute monarchy on the other; both can be tyrannical thought the former usually dissolves into a dictatorship as a strong-man emerges.  An absolute monarchy, like Saudi Arabia, cannot be classified as either a dictatorship nor a democracy and wouldn't fit on a continuum with those as the polar options.  To be honest, I'm not even sure that a continuum can accurately represent the variety of forms that a government can take.  I do think that the economic systems are classified correctly.  The third option, distributism, is not really a viable option and is only theoretical, as I understand it.