These drawings were done about 30 years ago. So many poses in life classes are too short, as if there becomes a problem when the model takes a break and resumes the pose. While quick poses are good, sustained poses are more important because the complexities and subtleties of the human form can be explored even more.
I can't remember which of these drawings was a 10 minute or 20 minute pose. The black and white ones are drawn with ink and the last two are oil paint wash.
David Hockney's line drawings and Degas' essence drawings (oil paint thinned with turps) were always an inspiration.