I am dumb... whats the code?

steuerung geht nicht ????

How do you open the Medical Directory ? I am guessing that the code is in the Medical Directory book but all I can do is rotate the book I can't open it. Has anybody figured out how to open the Medical Directory. There is no keyboard control option to show you what keyboard key does what. So far I learned if you hit E that interacts with things. Hit Z that makes things go slow motion Hit M and that makes your character go invisible. But no button I hit opens the book...