http://www.cbec.gov.in/customs/cs-act/formatted-htmls/cs-regu-idx.htm
http://www.cbec.gov.in/deptt_offcr/cs-manual2014.pdf
http://www.cbec.gov.in/customs/cscirc-mainbott.htm
http://www.cbec.gov.in/customs/cs-act/notifications/cs-notfns-idx.htm
http://www.cbec.gov.in/excise/cxrules/cx-rules-main.htm
http://www.servicetax.gov.in/st-rules-home.htm