Emigrants Return to England

[Marjorie]

Not sure if I have put this in the right place.

My family LEONARD E BROOKES (or Brooks), MRS EDITH ANN/IE BROOKES and GLADYS ROXANE BROOKES emigrated to Australia  in, I believe, 1926.  After the birth of their son, FRANK BROOKES, in Hurstville NSW in 1929 they returned to England sometime between 1930 and 1936.

So I am trying to trace their return (I have already posted an enquiry regarding their outward journey and received a lot of help and think I have traced them - but where do I search for return to England please?