1. Dermal implants: safety of products injected for soft tissue augmentation;Clark;J Am Acad Dermatol,1989
2. Injectable collagen for tissue augmentation;Wallace,1988
3. Skin filling: collagen and other injectables of the skin;Klein;Dermatol Clin,2001
4. Dermal filler materials and botulinum toxin;Naom;Int J Dermatol,2001
5. Facial soft tissue augmentation with autologus and homologous injectable collagen;Fagien,1998