Just a Thought

Three friends were studying at the library. Their names were Helga, Johannes, and Sebastian. Each person was studying a different subject (History, Journalism, and Science) and checked out a different number of books (2, 5, and 9.) The computer at the library was down for repairs that day. The Librarian wrote down the titles of the books and the names of the students. The next day when the computer was back on-line she had forgotten who checked out how many books and on which topic. Can you help her get this sorted out?

Here's what she remembers :

1. The students were not studying subjects that started with the same letter as their names.
2.The one who checked out the books on Journalism, checked out an even number of books.
3. The number of books about history was not a square number.
4.When he's not writing papers on the fall of Rome, Sebastian likes to read about ancient civilizations.