diff --git a/exercises/_18-ex-inference-tables.qmd b/exercises/_18-ex-inference-tables.qmd
index 7b0efbfa..1c5f656f 100644
--- a/exercises/_18-ex-inference-tables.qmd
+++ b/exercises/_18-ex-inference-tables.qmd
@@ -408,7 +408,7 @@
 \clearpage
 
 10. **Disaggregating Asian American tobacco use, smaller data.** Understanding cultural differences in tobacco use across different demographic groups can lead to improved health care education and treatment.
-    A recent study disaggregated tobacco use across Asian American ethnic groups [@Rao:2021].
+    A recent study disaggregated tobacco use across Asian American ethnic groups. [@Rao:2021]
 
     Consider the situation where the dataset is 50 times *smaller* than the original data (but have the same proportional representation in each category).
     The distribution of smokers in each of the ethnicity groups in the smaller data are as follows.