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What do you mean by "less strict"? Each referencing style is formatted differently to emphasize different parts of the entry, but they all require consistency (i.e.: you're not going to find a style that says something like, "place titles in italics only if you feel like it"). I suppose there might be some styles out there that have fewer formatting requirements, but the ones I am familiar with (APA, MLA, CMS, Turabian), are each different, not so much 'easier.' Personally, I like Turabian. It's a derivative of Chicago but, in my opinion, more flexible.