Comment by deggen

tl:dr;

Step 1. Find any and all errors in the bitcoin.pdf.

Step 2. Notice that [7][2][5] should be [2], [5], [7] conforming to IEEE or Vancouver standards.

Step 3. Use the error as a map: 7 => 2, 2 => 5, 5 => 7

Step 4. Extract the watermark from the references. Reference 7 letter 2 = C, Reference 2 letter 5 = S, Reference 5 letter 7 = W

There is a second message. Extraction method is linked github. Reveals DRCSWRIGHT