A presentation at Tech Talk @ Tagesspiegel by Gunnar Bittersmann
Logical vs. physical properties, values and units in CSS; encore: Trajan
The following resources were mentioned during the presentation or are useful additional information.
Jen Simmons at CSS Day 2017 + Browser API Special
several extra viewport sizes and accompanying viewport-relative units defined by the CSSWG
Why Hollywood kept using Trajan
Yves Peters at beyond tellerrand Düsseldorf 2011
The following code examples from the presentation can be tried out live.