API to get Problem report creator name and change request creator name from change notice object ?

Hi All,

i have a change notice object which is in resolved now, this process involves problem report , change request and finally change notice.

i want to sent an email weekly basis which includes all affected objects for that particular week, from change notice object i am able to get name of Change notice creator but i also need name of problem report creator n change request creator.

Is any API may i have to use to solve this requirement.

Regards,

Vivek