Encyclopedia Britannica isn't a primary source - your link doesn't even list the primary sources. Again, the primary sources I'm aware of (Josephus, the NT, Rabbinical literature) do not support that view and it shouldn't be accepted without further explanation.
Your link doesn't present an argument in favor of it's position, but if its author could, it looks like they would base it on the Sadduccee denial of the existence of the soul, resurrection, and angels. But there is no reason to believe that this was due to anything other than a different interpretation on the matter. The Pharisees took certain passages more individually and literally. For example, Ezek 37, which clearly talks in terms of resurrection could be taken to be talking about the restoration of Israel following exile. This could be the same with other resurrection passages - Pharisees took it to be literal and individual (as did Jesus), while the Sadducees apparently did not.
Or take another example on the existence of angels. If the Sadducee rejection of angels were also to be taken as rejection of books that mention angels (rather than simply a different interpretation on the issue), why would they accept the Torah itself which mentions angels (Gen 19:1, Gen 15, Gen 28.....)? In the case of angels, it's clear there was a difference in interpretation of the texts, not a rejection of texts. There's no reason to believe this wasn't the same on other doctrinal differences (resurrection, souls, afterlife) and just as they disputed with Pharisees over other interpretative matters dealing with Pharisee halakah.
Again, there is no evidence of a dispute between Pharisees and Sadducees over scripture. There is evidence of doctrinal disputes. halakic disputes, differences in interpretation, and a rejection of Pharisee oral law as binding. But there is no warrant for taking these disputes as indicating a rejection of scripture. An analogy would be when Protestants tell you that you reject scripture, but you would counter with a different interpretation rather than a rejection. That's what's happening here between Sadducees and Pharisees.