by Parbery, D.G
Published in Clean air (Heidelberg) (1974)

by Browne, L.W.B
Published in Clean air (Heidelberg) (1973)

by Fleming, A.K
Published in Clean air (Heidelberg) (1973)

by Lucas, D.H
Published in Clean air (Heidelberg) (1972)

by Strauss, W
Published in Clean air (Heidelberg) (1972)

by Bilger, R.W
Published in Clean air (Heidelberg) (1972)

by Treshow, M
Published in Clean air (Heidelberg) (1972)

by Fish, A.D
Published in Clean air (Heidelberg) (1972)

by Murphy, R.P, Pottinger, J.F
Published in Clean air (Heidelberg) (1971)