My family is Greek therefore I really enjoy and feel knowledgeable about the Greek culture. However I do not like to limit the sources I draw from and enjoy a range of diverse cultures.
Words, whether they are written on the wall, in books, in papers, in magazines, whether they are spoken in films, sung in songs, are just sput out by a passerby.
Islam, Pan-Asian ... and British manners!
French, Coco Chanel, Nature, Random
Sources? Isn't all source "Culture"? hmmmm. Sources are ever-present throughout life if one just pays attention. So I suppose my answer has to be, "everything". Of course, "everything" is constantly evolving. Many years ago I scoured magazines for images, while today I spend hours on the Internet...