RT:Journal article
AU:Egberts D, Santina X, Neebergen F
TI:Serum caffeine levels for diagnosis of caffeine addiction 
SO:Acta Energetica
YR:2001
VL:186
NO:12
PG:371

RT:Conference proceedings
AU:Gunnink F, Kanis T
TI:Diagnosis of caffeine addiction
SO:Abstracts of the Fourth International Conference on caffeine research
YR:2003
PG:101
CY:Sydney

RT:Correspondence
AU:Levelt S
SO:Personal communication
YR:2007

RT:Journal article
AU:Kanis T, Gunnink F
TI:Measuring serum caffeine levels in humans: a cross-sectional study
SO:Journal for addictive research
YR:2007
VL:3
NO:10
PG:34-39

RT:Journal article
AU:Van Nelle W, Smit A, Jones FH - Caffeine Research Group
TI:Spectrometry as method for caffeine level estimations
SO:International Spectrometry Journal
YR:1999
VL:12
NO:4
PG:1033-6

RT:Book
AU:Dorlas S, Egberts D 
TI:Questionnaires to measure caffeine addiction.
SO:Measuring caffeine addiction
YR:2006
PB:Grinder Press
CY:London

RT:Journal article
AU:Havelaar M, Dekkers ED, Brown J, Smith P
TI:Caffeine addiction in PhD students from Jakarta
SO:International Journal of Coffee and Related Drug Research
YR:2005
VL:16
NO:12
PG:370

RT:Journal article
AU:Smit F, Dorlas T, Gunnink F
TI:Questionnaires for different sorts of addictions 
SO:Acta Energetica
YR:2006
VL:656
NO:21
PG:1285
