by Ambrose, Skip, Ritchie, Robert J, Florian, Christine
Published in Northwestern naturalist (Olympia, Wash.) (01.10.2014)

by Ritchie, Robert J., Ambrose, Skip
Published in Arctic (01.06.1996)

by Allcock, Harry R, Ritchie, Robert J, Harris, Paul J
Published in Macromolecules (01.11.1980)

by Ritchie, Robert J, Harris, Paul J, Allcock, Harry R
Published in Inorganic chemistry (01.09.1980)

by Ritchie, Robert J
Year of Publication 21.03.2006

by RITCHIE ROBERT J
Year of Publication 21.03.2006

by Stickney, A. A., Ritchie, R. J.
Published in Arctic (01.03.1996)

by Ritchie, Robert J
Published in Scotsman (Edinburgh, Scotland : Daily) (22.08.2007)

by Ritchie, Robert J
Published in Journal of commerce (Newark, N.J.) (13.01.2003)

by RITCHIE; ROBERT J
Year of Publication 19.11.1985

by RITCHIE; ROBERT J
Year of Publication 28.05.1985

by Ritchie, Robert J., King, James G.
Published in The Natural History of an Arctic Oil Field (2000)

by Ritchie, Robert J
Published in The Ottawa citizen (1986) (22.08.1990)

by Ritchie, Robert J
Published in Journal of commerce (Newark, N.J.) (13.01.2003)

by RITCHIE, ROBERT J
Published in Railway Age (01.12.1999)

by ALLCOCK; HARRY R, RITCHIE; ROBERT J
Year of Publication 02.12.1980

by Ritchie, Robert J., Griesman, Henry, Young, Donald
Published in Archaeology (01.11.2000)

by ROBERT RITCHIE SPINK JR, DAVID WILLIAM BROWN SPINK
Year of Publication 16.12.1998

by KENT JOEL,HURST G. SAMUEL,RITCHIE R. H.,WARMACK ROBERT J.,BOULDIN DONALD W
Year of Publication 18.10.2006