White Spots on Smoke Rings by Bruce Nauman: A Case Study On Contemporary Art Conservation Using Microanalytical Techniques - Mafalda, Ana Cardeira; Câmara, Rodrigo Bettencourt da; Strzelec, Patrick; Schiavon, Nick; Mirão, José; Candeias, António; Carvalho, Maria Luísa; Manso, Marta (2015)