Looking for a white paper detailing experiences dealing with consistent UI [on hold]

A company is dealing with at least 3 major tech stacks: .NET, React and Ember. One of the challenges is keeping a consistent look and feel to standard elements such as dropdowns, calendars, etc.

Standardizing the approach with disparate technologies has been a challenge. Are there any white papers you can recommend detailing similar attempts to create a consistent look and feel with differing tech stacks?