The principal behind the corer is described in a number of scientific articles. One of the main authors of the articles is Ingemar Renberg, Professor at the Department of Ecology and Environmental Science, Umeå University, Sweden.
For convenience, two of the articles can be found under the below links:
The HON Kajak sediment corer; link to Journal of Paleolimnology. Also available here as PDF.
The HTH Sediment Corer; link to Journal of Paleolimnology.
Professor Ingemar Renberg
Dept of Ecology and Environmental Science
901 87 Umeå
Fasong Yuan, PhD
Dept. of Biological, Geological and Environmental Sciences
Cleveland State University
2121 Euclid Avenue
Cleveland, OH 44115 USA