| Friend, D R; Phillips, S J; Hill, J R (1991) Cutaneous effects of transdermal levonorgestrel. Food Chem Toxicol 29:639-46 |
| Catz, P; Friend, D R (1990) In vitro evaluations of transdermal levonorgestrel. Drug Des Deliv 6:49-60 |
| Friend, D R; Catz, P; Heller, J et al. (1989) Transdermal delivery of levonorgestrel. V. Preparation of devices and evaluation in vitro. Pharm Res 6:938-44 |
| Friend, D R; Catz, P; Heller, J et al. (1989) Transdermal delivery of levonorgestrel. IV: Evaluation of membranes. J Pharm Sci 78:477-80 |
| Friend, D R; Catz, P; Phillips, S (1989) Transdermal delivery of levonorgestrel. VII. In vivo studies. Contraception 40:73-80 |
