The reference for a brochure or pamphlet is basically the same as for a book, but with the addition of [brochure] in the Reference list as shown.
Trove allows you to search across multiple Australian collections at once (National Library of Australia n.d.)
National Library of Australia n.d., Trove [brochure], National Library of Australia, n.p..
In this example, the brochure does not have a date of publication, or a place of publication on it - n.d. indicates no date and n.p. indicates no place of publication.