muistikirjoilla
Muistikirjoilla is a Finnish noun phrase formed from muistikirja “memory book, notebook” plus the plural instrumental/adessive suffix -illa, meaning “with notebooks” or “using notebooks.” In Finnish, the form muistikirjoilla is used to indicate the means or instrument by which an action is performed, or the setting in which something happens. As a result, it often appears in sentences describing activities carried out using notebooks, such as writing, note-taking, or organizing information.
Etymology and morphology: muistikirja is a compound of muisti “memory” and kirja “book.” The plural form muistikirjat
Usage notes: In typical usage, muistikirjoilla answers questions “with what?” or “using what?” in the context