- Olof 'Ole' Hallstrom. // Waste & Recycling News;6/8/2009, Vol. 14 Issue 29, p31
The article presents an obituary for Olof Hallstrom, founder of Hallco Manufacturing Co.
- ROLL CALL. // Waste Age;Jul2009, Vol. 40 Issue 7, p12
The article announces the appointment of Steve Preston as president of Oakleaf Waste Management and reports the death of Olof Hallstrom, founder of Halloo Manufacturing Co.