Cita APA (7th ed.)

(2000). Ageproofing: 7 simple steps to super vitality at any age / Robert D. Willix, Jr.

Cita Chicago (17th ed.)

Ageproofing: 7 Simple Steps to Super Vitality at Any Age / Robert D. Willix, Jr. 2000.

Cita MLA (9th ed.)

Ageproofing: 7 Simple Steps to Super Vitality at Any Age / Robert D. Willix, Jr. 2000.

Atenció: Aquestes cites poden no estar 100% correctes.