R for Data Science (2nd Edition, in progress), Hadley Wickham, Garrett Grolemund, and Mine Çetinkaya-Rundel, 2023 - Online resource explaining data import and transformation using the Tidyverse in R.
I/O tools (text, CSV, HDF5, ...), The pandas development team, 2023 - Official guide to reading and writing data in various formats with pandas.
readr: Read Rectangular Text Data, Hadley Wickham, Jim Hester, and Lionel Henry, 2023 - Documentation for the readr package, which simplifies importing data into R.