| Content of Issue 4 DOI: 10.3217/jucs-021-04
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| Managing Editor's Column | C. Gütl | 502 | 
| Heuristic Algorithms for Manufacturing and Replacement Strategies of the Production System | R. Bucki, B. Chramcov, P. Suchánek | 503 | 
| RITA: a useR Interface evaluaTion frAmework | S. Charfi, H. Ezzedine, C. Kolski | 526 | 
| Sentiment and Behaviour Annotation in a Corpus of Dialogue Summaries | N. Trevisan Roman, P. Piwek, A.M. Brito Rizzoni Carvalho, A. Rossi Alvares | 561 | 
| Point Density Evaluation of Airborne LiDAR Datasets | B. Rupnik, D. Mongus, B. Žalik | 587 | 
| From Terminology Extraction to Terminology Validation:An Approach Adapted to Log Files | H. Saneifar, S. Bonniol, P. Poncelet, M. Roche | 604 |