1. Quality assurance and quality control of aseptic packaging;Ahvenainen;Food Review International,1988
2. Ultrasound penetration through different packaging materials - a non-destructive method for quality control of packed UHT milk;Ahvenainen;Lebensmittel-Wissenschaft und Technologie,1989a
3. Ultrasound imaging - a nondestructive method for control of the microbiological quality of aseptically packed foodstuffs;Ahvenainen;Lebensmittel-Wissenschaft und Technologie,1989b
4. Ultrasound imaging - a nondestructive method for monitoring the microbiological quality of aseptically-packed milk products;Ahvenainen;Lebensmittel-Wissenschaft und Technologie,1989c