Nursing Theorists

Hi there, I am a nursing student with a slight dilemma. I am supposed to be finding some information on a nursing theorist by the name of; Christensen/Christenson or similar. I would appreciate any help or advice.
Thank's

Hi Choppa. Do you by chance have a first name? I have done a search in all my text books and internet and cannot find any information on a theorist with that last name.