You can keep this in a pocket notebook.

您可以将其保存在便携式笔记本中。

youdao

Tools. I recommend a simple pocket notebook, and that’s it.

工具 我建议使用便利随身携带的记事本，这个就足够了。

youdao

Carry your pocket notebook and review the vocabulary frequently .

随身带上你的袖珍笔记本，时常复习英语字句。

youdao

Write down everything you spend (cash, check, credit or debit) in a blank check register, or a pocket notebook.

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Each carries a pocket notebook to log all incidents, which could later be used to help a police investigation.

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The idea is to have a notebook that fits in your pocket, so that you are not advertising yourself as a note-taker ideally, a small notebook that will not fall apart.

WSJ: Paul Theroux on Note-Taking | Word Craft