[1] A survey of named entity recognition and classification:
https://nlp.cs.nyu.edu/sekine/papers/li07.pdf
[2] Annotation Subtypes:
https://catalog.ldc.upenn.edu/docs/LDC2005T33/BBN-Types-Subtypes.html
[3] Named Entity Recognition and Resolution for Literary Studies:
https://pure.uva.nl/ws/files/2676433/168352_2014_VanDalenOskam_07_Namescape.pdf
[4] Conditional Random Fields: Probabilistic Models for Segmenting and Labeling Sequence Data:
https://repository.upenn.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1162&context=cis_papers
[5] Natural Language Processing: Semantic Aspects:
https://books.google.fr/books?id=YXv6AQAAQBAJ&source=gbs_navlinks_s
[6] Stanford NER:
https://nlp.stanford.edu/software/CRF-NER.shtml
[7] Testing NLTK and Stanford NER Taggers for Accuracy:
https://pythonprogramming.net/testing-stanford-ner-taggers-for-accuracy...