I'm no expert on this at all, but I'm sure I've seen citations with just Title (Author, date) so I would write that sentence: Trumbach, in his long-researched and anthropologically sophisticated work The Rise of the Egalitarian Family (Trumbach, 1978) has proposed ... I've added the author's name inside the parentheses, and removed the comma after the closing parenthesis. It's true that this duplicates the author's name, but I don't think that's a problem.
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