use of wildcard function recursively

[Aditya Kher]

list,
The wild card function will give list of *.c files in the current directory

SOURCE = $(wildcard *.c)

Is there any way to use wildcard to *find recursively* under given path
e.g.

SOURCE = $(wildcard source_dir/*.c)

where the directory structrure is

source_dir
 |
+-- dir_a
 |
+-- dir_b
 |
+-- dir_c

and in all these directories, *.c files are scattered all over?

-aditya