Illustrate an oil painting of Athena, the Greek goddess of wisdom, with a noble and defined jawline, portraying her divine strength. She should have a calm and sovereign expression, with unadorned hair styled in an elegant, classical Greek fashion, free of any headpieces. Her attire is regal, reflecting her status as a goddess, and should be adorned with symbols of wisdom and warfare, such as an owl or a spear, but without any armor or helmet. The background is a serene Grecian landscape, befitting her stature, all captured in the romantic style of William-Adolphe Bouguereau.