"See Saw Margery Daw"
From Tardis Wiki, the free Doctor Who reference
"See Saw Margery Daw" was an Earth nursery rhyme, the lyrics to which went as follows:
See Saw Margery Daw,
Johnny shall have a new master;
He shall have but a penny a day,
Because he can't work any faster.
In 2540, Jo Grant recited this rhyme (along with "Mary Had a Little Lamb" and "Humpty Dumpty") to counter the effects of the Master's hypnotism, claiming that, by filling her mind with nonsense, she couldn't be hypnotised. (TV: Frontier in Space [+]Loading...["Frontier in Space (TV story)"])