< Il Mistero del convento

• Geheimnisse einer Nonne
• Secret of a Nun

• Angela Benni as Angela Baron
• Deborah Wells
• Eva Henger as Eva Sodiesky, but not so credited in the original Italian version
• Ines as?
• Kathy Marceau as Ketty Berangé in the French version, may not be present in the original
• Katia Grimaldi as?
• Magdalena Lynn non-sex, plays the Mother Superior
• Simona Valli as Andrea Valente

The original credits do not match those given where the DVD Fievre is advertised for sale. The original credits are -

• Deborah Wells
• Andrea Valente
• Micaela Torrisi
• Kelly Brock
• Daniela Pancaldi
• Emanuela Sarno
• Lory Sebastian
• Christopher Clark
• Franco d'Alessi
• Mauro Riva
• Giacomo Sabelli
• Nicola Sabelli
• Sergio Ramona
• e con la participazione straordinaria di Magdalena Lynn

The only male in a sex role is Christophe Clark. Presumably Magdalena Lynn is the Mother Superior, a non-sex role.

Deborah Wells, Eva Henger and Simona Valli are clearly present. The first is credited and the last appears as Andrea Valente, but it is unclear who is who among the other names.

It seems that the French release Fievre is not an identical film, but uses part of the same footage and story, but removes the nuns theme. See more details.

And here.