Servus, I'm glad to have a respond to you. Before we start, I know your husband studied nursing in Austria. Is he a green card holder in the states? If yes, then he should have no issues applying for RN license in California. To begin with, he should browse the internet to find California Board of Registered Nursing. He should be able to download all of the required application forms. look for RN license by Examination. If there's any deficiency with your husbands nursing curriculum from Austria, the California Board of Nursing will provide lists of College institution in California. That means from my own knowledge, he has to start that missing subject course again clinical and practical! Alles gute!