10 awk tips - http://www.catonmat.net/blog/ten-awk-tips-tricks-and-pitfalls/

8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR - http://www.thegeekstuff.com/2010/01/8-powerful-awk-built-in-variables-fs-ofs-rs-ors-nr-nf-filename-fnr/

Tutorial of text editing commands - http://www.ibm.com/developerworks/aix/library/au-unixtext/index.html

wc and nl tutorial - http://www.thegeekstuff.com/2013/02/wc-nl-examples/ https://enkipro.com/insight/558ac712249a234c00842b68

tips for uniq, like show only items have duplications - http://www.thegeekstuff.com/2013/05/uniq-command-examples/

Tips of "cat", include display by column and by delimiter - http://www.thegeekstuff.com/2013/06/cut-command-examples/

Using lynx to convert HTML to text - https://enkipro.com/insight/558aaea45800843200bca364