This is the 5444th most frequent Russian word.
печатных
"Printed."
In this sentence, 'печатных' refers to 'printed,' describing the sources that are physically printed.
Она рекомендовала использовать больше печатных источников для нашего исследования.
She recommended using more printed sources for our research.
Here, 'печатных' modifies 'изданий' to describe publications that are printed.
Качество печатных изданий этой типографии всегда на высоком уровне.
The quality of printed editions from this printing shop is always high.
In this example, 'печатных' describes 'технологий' which refers to technologies employed in the printing process.