Centre for Health Protection - Breast Cancer
US Top 40 Singles For The Week Ending May 23, 1981 - Top40Weekly.com
List of Billboard Hot 100 number ones of 1981 - Wikiwand
Billboard Year-End Hot 100 singles of 1981 - Wikiwand
Billboard Top Hits: 1981 - Wikipedia
Making and Breaking Time Online – Jim McGrath, PhD
Dolly Parton's '9 To 5': Rewinding The Charts – Billboard
1981 Billboard Top 100 | Popnable
Billboard Hot 100 Charts: The 1970s - Record Research
Top 100 Singles
All US Top 40 Singles For 1981 - Top40Weekly.com
100 Greatest Albums of 1981
Evolution of Billboard Hot 100 Chart Design | Spencer.com Wiki | Fandom
The Official Top 50 best-selling songs of 1980
Real Life And Real Charts: Record Business Top 100 charts
Billboard Hot R&B Hits: 1981 - Wikipedia
Updates | The Record index
The Hot 100 – Billboard
