There are many excellent, comprehensive research guides to international taxation law covering:
Two recommended guides are:
Some resources described in these guides are only available to those affiliated with the institution, however they also list many freely available materials.
These international databases are useful for comparative taxation research as well as research on a specific topic:
Contains full-text journals, dissertations, working papers and country and industry focused reports.
Accounting, Tax & Banking Collection
Global scholarly journals in accounting, tax, banking and business.
Full-text and peer reviewed journals covering accounting, banking and finance.
Covers a wide range of economics related literature.
Contains national, international and regional newspapers, news wires, podcasts and company reports.
The world's largest image-based legal research database.
Contains law reviews, legal newspapers and specialist publications.
US federal and state law sources, international law and laws of some non-US jurisdictions.
Full-text cases, legislation and journal articles from a range of jurisdictions, but mostly US and Canada.
Contains cases, legislation, journals articles, commentary and EU legal materials.
For resources on Australian tax law, go to the Taxation resource guide.
Canadian cases and legislation can be found on CanLII.
The principal Act is the Income Tax Act , RSC 1985, (5th Supp) c1.
Hein Online contains the Canada Supreme Court Reports and the Revised Statutes of Canada.
Oversees the development of tax law and other measures, including legislation governing banks and other federal financial institutions.
Includes regulations made under the Act and amendments not in force.
New Zealand Legislation is the official NZ legislation site.
Cases and legislation can also be found on NZLII.
The New Zealand Law Reports are available from Lexis Advance Pacific.
CPA Australia: New Zealand contains tax checklists, sample taxation letters and information on practising and auditing in New Zealand.
An excellent guide to UK taxation is Oxford LibGuides: Tax law from Oxford University Library.
The official site for UK legislation is legislation.gov.uk.
ICLR Online contains the Law Reports including Appeal Cases (AC), Chancery (Ch), Queen's Bench (QB) and King's Bench (KB), and the Weekly Law Reports (WLR).
Cases and legislation can also be found on BAILII.
An excellent guide to US taxation is Federal Tax Research: Outline & Guide Information from the New York University Law Library.
Cases and legislation are available from the Legal Information Institute (LII).
Lexis Advance US and Thomson Reuters Westlaw have extensive coverage of US cases, legislation and commentary.