written by Richard Walker and others. written by Sarah Baxter [and 17 others]. written by Richard Walker. written by Richard Walker ; consultant, Robert Winston. written by Laura Buller and Tori Kosara. written and researched by Sara Benson and 6 others. written by Rachel Walker. written by Mark Andrew [and thirty-one others]. written and researched by Sarina Singh [and others] written and researched by China Williams [and 9 others].