What is the best way to convert .vob files copied directly from a DVD into a format usable by Premiere Pro? I need to import some video material that was copied directly from a DVD into Premiere Pro. (Disclaimer: This is for educational purposes, in that context it is lawful to use excerpts of commercial films in Germany). 

They were directly copied, meaning I don't have an image of the DVD, but the original file structure from the DVD including the folders VIDEO_TS and AUDIO_TS, containing .VOB files. Premiere Pro can't import them. 

What is the best way to convert/copy those files to get them into a format that Premiere Pro can use? By 'best' I mean with the least quality loss possible and in a way that will produce either one file that has the entire movie in them or an array of sorted files that will be easy to look through. No I don't have the original DVD. Thanks!
Using ffmpeg, cat and remux all the VOBs together to a MPEG program stream.

ffmpeg -i "concat:vts01_1.vob|vts01_2.vob|vts01_3.vob" -c copy -f dvd dvd.mpg


(You may have to escape the | character i.e. vts01_1.vob\|vts01_2.vob\|vts01_3.vob)