You're just linking to a political accusation. Apple uses Irish tax law to create a "stateless" holding company. They don't pay taxes on the money booked into that company since it is not affiliated with any country. However, as soon as they want to spend that money or book it as profits, they pay taxes on it in whatever country it is used or booked (usually the US.)
As I said, taxes are delayed, not avoided. And certainly not tax evasion, since they are following Irish law.
The "research" is made up for shock value. They're just using numbers that assume that all revenue generated in the EU will be booked in the EU. That's not reality. In accordance with international tax law, the majority of the revenue is booked in the country where the value is created. For Apple, that's obviously the US.