by Helfert, M.R
Published in Entomol News Philadelphia (1972)

by Helfert, M.R. (NASA/Johnson Space Center, Houston, TX), Lulla, K.P
Published in Photogrammetric engineering and remote sensing (01.10.1990)

by Pitts, D.E., Helfert, M.R., Lulla, K., Bremer, J.M., Evans, C.A., Heydorn, J., Dardano, C., Willis, K.
Published in Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium (1994)

by Nerem, R.S, Holz, R.K, Helfert, M.R, Tapley, B.D
Published in GeoJournal (01.12.1985)

by Evans, C.A., Helfert, M.R., Helms, D.R.
Published in [Proceedings] IGARSS '92 International Geoscience and Remote Sensing Symposium (1992)