Worldwide
Luxury Retreats International, Inc.: https://www.luxuryretreats.com/; 5530 Rue Saint-Patrick Bureau 2210, Montréal, QC, Canada, H4E 1A8.
Villas.com: http://www.villas.com/; a part of Booking.com.
Villas of Distinction: http://www.villasofdistinction.com/;
Caribbean
Villas Caribe by TravelKeys.com: http://www.villascaribe.com/; Caribbean destinations.
Italy
In Italy: http://www.initaly.com/; 877 655-9221, villas, convent or monastery, and youth hostels.
Parker Villas: http://www.parkervillas.com/; 800 280-2811, Italy Vacation Rentals – Certified Homes, Villas, & Apartments for 22 years.