1. The perception of odors;Engen,1984
2. Psychophysics the fundamentals;Gescheider,1984
3. An olfactorium;Foster;Am J Psych,1950
4. Reproducibility and sensitivity of oral malodour measurements with a portable sulfide monitor;Rosenberg;J Dent Res,1991
5. Critical thinking: understanding and evaluating dental research;Brunette,1996