diff --git a/intermediate/data_cleaning/05.1_intro.md b/intermediate/data_cleaning/05.1_intro.md
index 9646f6b4..ccfe05e4 100644
--- a/intermediate/data_cleaning/05.1_intro.md
+++ b/intermediate/data_cleaning/05.1_intro.md
@@ -19,6 +19,7 @@ Tidy data was developed by Hadley Wickham for tabular datasets in the R programm
 The concept of [tidy data](https://vita.had.co.nz/papers/tidy-data.pdf) was developed by Hadley Wickham in the R programming language, and is a set of principles to guide facilitating tabular data for analysis.
 
 {attribution="Wickham, 2014"}
+
 > "Tidy datasets are all alike, but every messy dataset is messy in its own way."
 
 Wickham defines three core principles of tidy data for tabular principles. They are: