Later in the article he mentions that [7] was a study of her mood swings.

[4] Broman, Chad 2015 Why is Valentine’s Day so Important? A Time Analysis of Tiffany’s Relationship Expectations :: Journal of Psychological Machine Learning

[5] Broman, Chad 2016 A Play by Play Analysis of Purchasing a Luxury Speedboat during an out of Wedlock Pregnancy Scare :: Journal of Psychological Machine Learning

[6] Broman, Chad 2016 The Mood Metric Equivalent Measurement: How to Get Away with a 150$ Bar Tab :: Journal of Psychological Machine Learning

[7] Broman, Chad 2021 A Time Series Analysis of My Girlfriend’s Mood Swings :: Journal of Astrological Big Data Ecology