International Friends of Nature. (1991). Everybody's talking about soft tourism: We're doing something about it! : ten practical examples of what the Friends of Nature have done. International Friends of Nature.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)International Friends of Nature. Everybody's Talking About Soft Tourism: We're Doing Something About It! : Ten Practical Examples of What the Friends of Nature Have Done. Vienna: International Friends of Nature, 1991.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)International Friends of Nature. Everybody's Talking About Soft Tourism: We're Doing Something About It! : Ten Practical Examples of What the Friends of Nature Have Done. International Friends of Nature, 1991.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.