The word "账簿" is formed by combining the character "账", meaning "account", which uses the radical "贝" (shell, historically representing currency) to indicate financial matters and the phonetic component "长" for sound, with the character "簿", meaning "book" or "register", which uses the radical "竹" (bamboo, referring to early writing surfaces) to indicate a document and the phonetic component "溥" for sound; together, they semantically specify a book used for keeping financial accounts.