The Sister of Ursula (1978)

After the untimely death of their father, sexy brunette sisters Dagmar (Stefania D'Amario) and Ursula (Barbara Magnolfi) go in search of their estranged mother, with whom they intend to share their inheritance. Checking in at a luxurious hotel on the Amalfi coast proves to be a mistake when a mysterious killer starts to bump off the more promiscuous guests.