yes he definitely referred to all the constitutions, british in particular but to say he copied it from somewhere is sheer childish thought. For a such big document referances and certain as it is adaptation is necessary. For your information the team had ro write as many as 6 articles as per Indian culture and conditions - eg. Hindu undivided family law (Do u think he copied it from ...say Canada ) Its politicians of today along with some "brainy" lawyers who are twisting the meaning of our constitutions. Lastly you have power as a citizen to push for any constitution ammendment, do it instead of criticising that great man.
