Well there's quite a lot there in that pdf describing strength of the steel columns in technical terms, the Johnson Parabola equation used in engineering to determine the critical
buckling stress for inelastic buckling and so on. There's a lot to chew on really.Then summarise the argument into a few concise sentences, and add quotes from the text that support and clarify your summary.
You seem to expect us to do what NIST and their unscientific lackies Bazant and Greening have failed to do, which is to thoroughly investigate and explain why three building collapsed after two plane collisions and in scientific analysis that satisfies independent scrutiny. I'm sorry, it's not our job to convince 900 engineers and tens of millions of Americans and Canadians that they did the job right in the first place. If the buildings fell down due to shoddy workmanship, then hundreds of engineers want to be able to understand it in great detail so as to avoid design flaws in future. The feds spent far more money on a Columbia space shuttle disaster, and a lot more money on investigating a Clinton-Lewinsky sex scandal, and a lot more money to investigate a Whitewater scandal than was spent on discovering why three white elephants collapsed in the heart of New York City. Hundreds of engineers don't necessarily care whether it was an inside job or not - they need to know because it's among their career obligations to understand what really happened.