Grants, scholarships and bursaries are generally available at the institutions that you are studying, speak to the financial aid office and they should point you in the right direction including which academic departments are offering funding for postgraduate studies.
Then generally there are a few global websites which can help, because they either offer solutions for general post grad studies in terms of Grants, scholarships or bursaries or are specifically based for certain areas. Search through them and you should win. A lot of post grad studies covers funding just for studying a masters/PhD as a blanket offering, so at times it doesn’t matter what field you are reading for in your degree.

Check out the following useful websites: probably the best international student financial solution website around. It has a database of student funding options from all around the world. 

Postgraduate Studentships: Another UK based website that covers all post grad funding options.
College Is an American based student funding website which has a breakdown of various options available in the USA.