Nursing opportunities in doctor's offices

I would like to search for an RN position at a doctor's office or clinic. How do I go about finding a job like that. I've looked in the papers and I see no job positions for doctor's offices, but, mainly hospitals and nursing homes. I live in Missouri. Thank you.
Try Craigslist...in my area, there are frequent postings for physician office positions. Or, you could try cold calling some of the bigger clinics you know of in town and ask if they have any job openings.