Access to the Walt Disney video. (There is another non-Disney version available from Legendwhich which could be used in a similar way, but the exercise offered below would need amendment) and/or
The audio-cassette and booklet based on the Walt Disney version - Pickwick Children's Disney Read-along Collection, available from major retailers.
If possible, a collection of ads, merchandising, reviews and any other memorabilia, for instance on the internet, associated with the launch of the Disney version for follow-up work on marketing.
Resources on the internet that can be used:
The Annotated Little Mermaid, The SurLaLune Fairy Tales Pages. Includes links to various illustrations of the tale and stories which have inspired Andersen to write The Little Mermaid, including Undine (1811) by Friedrich de la Motte Fouque.