@article{stefanova:hal-00069184, TITLE = {{Preserved lignin structures in Miocene-aged lignite lithotypes, Bulgaria.}}, AUTHOR = {Stefanova, Maya and Maman, O. and Guillet, Bernard and Disnar, Jean-Robert}, URL = {https://insu.hal.science/hal-00069184}, JOURNAL = {{Fuel}}, PUBLISHER = {{Elsevier}}, VOLUME = {83}, PAGES = {123-128}, YEAR = {2004}, DOI = {10.1016/S0016-2361(03)00037-1}, KEYWORDS = {Coal ; Lignin ; Capillary electrophoresis}, PDF = {https://insu.hal.science/hal-00069184/file/JRDisnar-Fuel-2004.pdf}, HAL_ID = {hal-00069184}, HAL_VERSION = {v1}, }