In English the currency symbol is typically before the number, whereas especially in Europe (with exceptions e.g. Switzerland) it is typically after the number. The title here is kind of correct in English I'd say, but the author is Dutch who happens to write in English.
In the before-times (before the euro), we dutch used to write fl123,45 So putting the euro symbol in front comes naturally.
Interesting, I knew that it was written $1 for dollar but thought it depends on the currency, not the language.
In Dutch the currency symbol always comes before the number as well, so this is intentional of the author.
Dan was my masters advisor and he’s Canadian, they used the French “spelling” because it’s a French paper.
At least with American currency it varies, e.g. one dollar is $1 while one penny is 1¢.