this edition written and researched by Nicola Williams and three others. this edition written and researched by Emilie Filou and three others. this edition written and researched by China Williams and six others this edition written and researched by Iain Stewart and three others. this edition written and researched by Sandra Bao and three others this edition written and researched by Korina Miller and seven others. this edition written and researched by Neil wilson and nine others. this edition written and researched by Regis St Louis and three others this edition written and researched by Neil Wilson and seven others. this edition written and researched by Karla Zimmerman and eight others.