the invention of the refrigerator with self-contained unit occurred in 1923
self_contained is contained. on_selection is 1920_silent_film. hp_503296_b21 is not computer_redundant_power_supply. self_powered_vehicle is not consumer_durable. refrigerator is not machine. self_contained is not contained. self_powered_vehicle is consumer_durable. computer_redundant_power_supply is computer_power_supply.