White Plastic Toilet Sink – 15.25” – 20.” Surface Mount Utility Toilet Tank Sink Cover w/Built-In Faucet & Sink for Handwashing & Flushing - Apartment Must Haves for Space & Water Conservation - Amazon.com
2 in 1 Close Coupled Toilet and Basin Compact Combo with Seat Set Space Saver | eBay
Silent Venus Ceramic Sink for Toilet Tanks (White) - Toilet Tank included - Toilet Tank Sink Combo - Toilet Top Sink for Small Bathrooms - Made of Ceramic - Amazon.com
Are Sink-Toilet Combinations Common in Japan? | Snopes.com
water - Switching to Toilet/Sink Combo - Sustainable Living Stack Exchange