Course reader for session 4

For session 4 on May 24th, read the following papers from the course reader:

- Araujo & Brereton (1996) Experimental design II. Optimization, TrAC Trends in Analytical Chemistry (10.1016/0165-9936(96)80762-X)

- Leardi (2009) Experimental design in chemistry: a tutorial, Analytica Chimica Acta (10.1016/j.aca.2009.06.015)