Research on unwritten constitutions is helpful to expanding the scope of constitution study enrichment of its contents and balance of its structure .

对 不 成文宪法的专门研究，将有助于 宪 法学研究领域的拓展、内容的丰富和结构的平衡。

Britain has an unwritten constitution and the United States has a written constitution .

英国有 不 成文 的 宪法，美国有成文的宪法。

The clarifying the characteristics of formation and forms of unwritten constitution is the basis for distinguishing the written and unwritten constitutions .

以 两 类不同 宪法类型的特征为标准，就能够对不 成文宪法国家类型形成 较为清晰的判断。