- write "et al." as `et~al.\`, or `et~al.` if it's followed immediately by punctuation such as a comma or bracket.
view size of directories within current directory with
- `du -hs ./*` (-h for human readable, -s for summary, ./* because otherwise it just tells you size of current dir), or
- `du -hd 1` (-d for depth to search down, with 1 being that depth).