These episodes are lost in the past.

Only 24 episodes are thought to survive; other episodes were wiped, discarded or lost.

For many years there were persistent rumours-fuelled by press statements from Bond himself-that some episodes had been lost or destroyed.

Many old episodes of the show were destroyed and are lost forever.

Although five episodes transmitted in 1974-1975 are still lost, Mornington Crescent seems to have made no appearance before 1978.

The whole episode could more productively have been lost.

The episode has not been lost on Warrick.

However, as the live (kinescoped) episodes are largely lost, Mama is unfamiliar to later generations of viewers.

All six episodes were lost in the BBC's stock clearance of the 1970s.

Many episodes of popular Australian commercial TV series are also lost.