Your school library should have articles available for free. You'd be surprised how many students I encounter who don't fully understand what's available through their own school libraries. You might have to make a trip in there and actually talk to one of the staff members, but they can usually show you how to access the materials they have phyisically stored in the building itself (that you can xerox cheaply) ... and/or ... they can show you how to access the journals they subscribe to online. Many libraries subscribe to services that give them access to a wide range of journals either on computers in the library or from home -- but you have to know how to use the system.
Most hospitals also have libraries that you could go to. For example, you could drop in the library after your clinical experience and get the articles you need for your upcoming assignments -- all for free. It just takes a little planning ahead.