Update metadata in dataset card (#7)

- Update metadata in dataset card (190f2aaa980f5749b4b3d27ee399fbb225a18124)

README.md

@@ -21,7 +21,7 @@ language:
 - ru
 - sv
 license:
-- unknown
+- other
 multilinguality:
 - multilingual
 size_categories:
@@ -1316,7 +1316,7 @@ configs:
     path: it-sv/train-*
 ---
 
-# Dataset Card for OpusBooks
+# Dataset Card for OPUS Books
 
 ## Table of Contents
 - [Dataset Description](#dataset-description)
@@ -1344,30 +1344,55 @@ configs:
 
 ## Dataset Description
 
-- **Homepage:** http://opus.nlpl.eu/Books.php
-- **Repository:** None
-- **Paper:** http://www.lrec-conf.org/proceedings/lrec2012/pdf/463_Paper.pdf
+- **Homepage:** https://opus.nlpl.eu/Books/corpus/version/Books
+- **Repository:** [More Information Needed]
+- **Paper:** https://aclanthology.org/L12-1246/
 - **Leaderboard:** [More Information Needed]
 - **Point of Contact:** [More Information Needed]
 
 ### Dataset Summary
 
-[More Information Needed]
+This is a collection of copyright free books aligned by Andras Farkas, which are available from http://www.farkastranslations.com/bilingual_books.php
+Note that the texts are rather dated due to copyright issues and that some of them are manually reviewed (check the meta-data at the top of the corpus files in XML). The source is multilingually aligned, which is available from http://www.farkastranslations.com/bilingual_books.php.
+In OPUS, the alignment is formally bilingual but the multilingual alignment can be recovered from the XCES sentence alignment files. Note also that the alignment units from the original source may include multi-sentence paragraphs, which are split and sentence-aligned in OPUS.
+All texts are freely available for personal, educational and research use. Commercial use (e.g. reselling as parallel books) and mass redistribution without explicit permission are not granted. Please acknowledge the source when using the data!
+
+Books's Numbers:
+- Languages: 16
+- Bitexts: 64
+- Number of files: 158
+- Number of tokens: 19.50M
+- Sentence fragments: 0.91M
 
 ### Supported Tasks and Leaderboards
 
-[More Information Needed]
+Translation.
 
 ### Languages
 
-[More Information Needed]
+The languages in the dataset are:
+- ca
+- de
+- el
+- en
+- eo
+- es
+- fi
+- fr
+- hu
+- it
+- nl
+- no
+- pl
+- pt
+- ru
+- sv
 
 ## Dataset Structure
 
 ### Data Instances
 
-Here are some examples of questions and facts:
-
+[More Information Needed]
 
 ### Data Fields
 
@@ -1433,11 +1458,35 @@ Here are some examples of questions and facts:
 
 ### Licensing Information
 
-[More Information Needed]
+All texts are freely available for personal, educational and research use. Commercial use (e.g. reselling as parallel books) and mass redistribution without explicit permission are not granted.
 
 ### Citation Information
 
-[More Information Needed]
+Please acknowledge the source when using the data.
+
+Please cite the following article if you use any part of the OPUS corpus in your own work:
+```bibtex
+@inproceedings{tiedemann-2012-parallel,
+    title = "Parallel Data, Tools and Interfaces in {OPUS}",
+    author = {Tiedemann, J{\"o}rg},
+    editor = "Calzolari, Nicoletta  and
+      Choukri, Khalid  and
+      Declerck, Thierry  and
+      Do{\u{g}}an, Mehmet U{\u{g}}ur  and
+      Maegaard, Bente  and
+      Mariani, Joseph  and
+      Moreno, Asuncion  and
+      Odijk, Jan  and
+      Piperidis, Stelios",
+    booktitle = "Proceedings of the Eighth International Conference on Language Resources and Evaluation ({LREC}'12)",
+    month = may,
+    year = "2012",
+    address = "Istanbul, Turkey",
+    publisher = "European Language Resources Association (ELRA)",
+    url = "http://www.lrec-conf.org/proceedings/lrec2012/pdf/463_Paper.pdf",
+    pages = "2214--2218",
+}
+```
 
 ### Contributions