diff --git a/vignettes/references.bib b/vignettes/references.bib
index 57604635..879be004 100644
--- a/vignettes/references.bib
+++ b/vignettes/references.bib
@@ -1,3 +1,16 @@
+@article{chandler,
+author = {Chandler, Conor O. and Proskorovsky, Irina},
+title = {Uncertain about uncertainty in matching-adjusted indirect comparisons? A simulation study to compare methods for variance estimation},
+journal = {Research Synthesis Methods},
+volume = {15},
+number = {6},
+pages = {1094-1110},
+keywords = {bootstrap, matching-adjusted indirect comparison, robust sandwich estimator, simulation study, uncertainty, variance},
+doi = {https://doi.org/10.1002/jrsm.1759},
+url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jrsm.1759},
+year = {2024}
+}
+
 @article{Bucher,
 title = {The results of direct and indirect treatment comparisons in meta-analysis of randomized controlled trials},
 journal = {Journal of Clinical Epidemiology},
diff --git a/vignettes/unanchored_binary.Rmd b/vignettes/unanchored_binary.Rmd
index d1f8652f..df0b69c5 100644
--- a/vignettes/unanchored_binary.Rmd
+++ b/vignettes/unanchored_binary.Rmd
@@ -162,3 +162,7 @@ result_boot <- maic_unanchored(
 
 result_boot$inferential$fit$boot_res_AB
 ```
+
+Note that the bootstrap in unanchored analysis only uses resampling of internal IPD trial population and assumes there is no uncertainty in the comparator trial population (i.e. estimated mean outcomes). [@chandler] Therefore, we recommend the use of sandwich estimators for the variance calculation in the unanchored analysis.
+
+# References
diff --git a/vignettes/unanchored_survival.Rmd b/vignettes/unanchored_survival.Rmd
index 10a76ba9..fc8b4b4d 100644
--- a/vignettes/unanchored_survival.Rmd
+++ b/vignettes/unanchored_survival.Rmd
@@ -165,3 +165,7 @@ result_boot <- maic_unanchored(
 
 result_boot$inferential$fit$boot_res_AB
 ```
+
+Note that the bootstrap in unanchored analysis only uses resampling of internal IPD trial population and assumes there is no uncertainty in the comparator trial population (i.e. estimated mean outcomes). [@chandler] Therefore, we recommend the use of sandwich estimators for the variance calculation in the unanchored analysis.
+
+# References