In the wake of more WWII/Nazi era stolen art legal battles, the International Foundation for Art Research (IFAR) has issued a new Provenance Guide, which highlights the importance of archival research, and states that provenance research is “a must” for all art purchasers.  The Provenance Guide includes links to numerous archival websites and databases (including the Getty Research Institute), which will aid in provenance due diligence.  IFAR states that provenance litigation demonstrate that “all available archival materials must be consulted . . . ” because among other things, “documentary evidence may be open to interpretation.”