Helbig, K. L., Nothnagel, M., Hampe, J., Balschun, T., Nikolaus, S., Schreiber, S., . . . Nöthlings, U. (2012). A case-only study of gene-environment interaction between genetic susceptibility variants in NOD2 and cigarette smoking in Crohn's disease aetiology. BioMed Central.

Helbig, Katherine L., Michael Nothnagel, Jochen Hampe, Tobias Balschun, Susanna Nikolaus, Stefan Schreiber, Andre Franke, i Ute Nöthlings. A Case-only Study of Gene-environment Interaction between Genetic Susceptibility Variants in NOD2 and Cigarette Smoking in Crohn's Disease Aetiology. BioMed Central, 2012.

Helbig, Katherine L., et al. A Case-only Study of Gene-environment Interaction between Genetic Susceptibility Variants in NOD2 and Cigarette Smoking in Crohn's Disease Aetiology. BioMed Central, 2012.