Viagra. Molecular model of the drug sildenafil citrate,marketed under the brands Viagra and Revatio. Atoms are represented as spheres and are colour-coded: carbon (grey),hydrogen (white),nitrogen (blue),oxygen (red),sulphur (yellow) | |
Licence : | Libre de droits |
Crédit: | Science Photo Library / Laguna Design |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |