The ornamental design for a refrigerator, as shown and described.
1. Refrigerator
1.1 : Perspective
1.2 : Perspective view 2
1.3 : Perspective view 3
1.4 : Perspective view 4
1.5 : Front
1.6 : Enlarged view of the area enclosed in dash-dot broken lines in 1.1
1.7 : Enlarged view 2 of the area enclosed in dash-dot broken lines in 1.2
1.8 : Enlarged view 3 of the area enclosed in dash-dot broken lines in 1.3
1.9 : Enlarged view 4 of the area enclosed in dash-dot broken lines in 1.4
1.10 : Front view showing that the displays on the top of the dispenser are being operated and included for the purpose of demonstrating a condition of use and form no part of the claimed design
The broken lines depict portions of the refrigerator that form no part of the claimed design; the dash-dot broken lines define the boundary of the claimed design and form no part thereof.