Noise of Current Diesel Engines 
B J Challen
British Acoustical Society Proceedings
Summer 1973, Vol.2, number 2.
Noise Reduction of Present Generation Diesel Engines
C C J French and B J Challen 
CIMAC 10th International Conference
Washington 1973
The Effect of Combustion System on Engine Noise
B J Challen
SAE 750798, 1975
Passenger Car Noise - Diesel and Gasoline
B J Challen and D Morrison
Noise Control Engineering Conference 1978
Data Recording and Processing from Engine Noise Test Cells
B J Challen and M P North 
Transducer 79 Conference, London 1979
A Practical Approach to Truck Noise Reduction
K A Atkins and B J Challen
IMechE C131/79  1979
Passenger Car Noise Control Measures and their Effects on Fuel, Economy, Weight and Cost
D Morrison, B J Challen and T Trella
SAE 800439, 1980
Transient and Steady State Noise in Automotive Diesel Engines
B J Challen, K A Atkins and M D Croker
Institute of Acoustics Conference on Diesel Engine Noise Research, 1980
An Engineering Index of Diesel Engine Idling Noise
B J Challen and A Kuczora
InterNoise 80, US Noise Control Engineering Conference, Miami 1980
Techniques for Engine Noise Control
B J Challen
General Motors Conference on "Engine Noise, Excitation, Vibration and Radiation"
Warren, Michigan, 1981
A Review of Recent Progress in Diesel Engine Noise Reduction
B J Challen and D M Croker
SAE 820517  1982
Engine Noise Test Cells - Are Special Rooms Still Needed?
M D Croker and B J Challen
Institute of Acoustics, London, 1982
Transient Testing of Diesel Engines
C A Clark, M P May and B J Challen
SAE 840348  1984
Examining High Speed Data During Engine Transients
C A Clark and B J Challen 
SAE 850402   1985