This series takes a look at 3 different forms of power supply. Books in series 606e - There were 3 titles published in this series. Both entries below describe the first edition of each title.
In 1999, when the Ladybird factory closed, the last books to come out of the bindery were 210 hand-made versions of Tootles the Taxi (series 413) - one for each member of staff as a leaving gift
