Alistair Moffat Neil Sharman Ian H. Witten Timothy C. Bell An Empirical Evaluation of Coding Techniques for Multi-Symbol Alphabets. 108-117 1993 conf/dcc/1993 Data Compression Conference db/conf/dcc/dcc93.html#MoffatSWB93 https://doi.org/10.1109/DCC.1993.253139