Human Rights of Roma and Travellers in Europe:      3 European Studies
I have been incredibly lucky in having had the chance to work closely for close to a year with Thomas Hammarberg, during 2012-2013, in examining human rights issues in the Transnistrian region of the Republic of Moldova.   There are few people alive from whom one can learn more about the art of human rights.   Before then, I worked with Gwendolyn Albert on Thomas's 2012 report on the Human Rights of Roma and Travellers in Europe, while he was still Council of Europe Human Rights Commissioner.  It is still the definitive document on the subject.  
Prior to that, I wrote two other major European studies on Roma issues:     Arthur Ivatts and I co-wrote the 2004 European Commission report "Roma in an Enlarged European Union".    In 2008 and 2009, Elspeth Guild and myself co-authored a study on Roma migration in Europe, including the complex legal frameworks at issue.    The latter study was commissioned by the OSCE High Commissioner for National Minorities, together with then-Council of Europe Commissioner Hammarberg.
I am sharing all three studies on buttons to the left, as I believe they all stand the test of time in their own ways,         
Children in the Schinoasa Roma community, Calarasi County, Republic of Moldova, 2013 
Human rights of Roma
and Travellers in Europe (2012 Hammarberg Report)
Recent Migration of Roma in Europe (2009 OSCE HCNM Study)
Roma in an Enlarged European Union (2004 European Commission Study)

Human Rights in Transnistria 

I managed to work with Thomas once more, in 2102 and 2013.    A confluence of opportunities enabled the UN to engage Thomas Hammarberg to examine human rights in the separatist Transnistrian region of the republic of Moldova in early 2012, just as power changed hands for the first time in Transnistrian history.    In this engagement, Thomas did the writing and I provided support.  Thomas and I ultimately spent 25 days there, trying to meet and see as much and as diverse a range of people and institutions as was possible.   The result was as much of a comprehensive report as we could muster, published in February 2013.   The result, I hope, was to humanize the people and issues living on the other bank, to endeavour to switch off the conflict megaphone with which they are usually discussed, and to examine issues in Transnistria through a human rights lens, in the same way we examine issues in any other place.    It is among the first human rights reports of its kind, and I believe it has made a genuine contribution conceptually to human rights reporting concerning territories not under the control of the state.
Report in English
Report in Russian
Report in Moldavian or Romanian
European Roma Rights Centre Country Reports
Between 1996 and 2007 pretty much everything published by the European Roma Rights Centre crossed my desk, and I had a major hand in our research undertakings, including direct field research in many contexts.   I cannot possibly include here all of the publications of that period, so I am putting up here 5 favorites:
1.   A Special Remedy:       our 1999 report on racially segregated education in the Czech Republic, launched the same day as the lawsuit which ultimately because the European Court of Human Rights judgment in D.H. and Others v. Czech Republic.     Few human rights research efforts manage to gather this much powerful statistical data.
2.    Campland:       possibly our most powereful report.  We reshaped discourse around Italian policy vis-a-vis Roma.   Few were previously prepared to see practices in western Europe as racial segregation.   Ultimately followed by a series of powerful decisions by the European Committee of Social Rights.
3.   State of Impunity:     a 2001 revisit of issues in Romania, including the then-state of efforts to secure justice in a series of murderous pogroms during the period 1989-1991 (these were ultimately successful, in the European Court of Human Rights judgments beginning with Moldovan and Others v. Romania, be we could not know that then).
4.    Always Somewhere Else -- It was "Hors d'ici" -- "Get out of here!", in the French translation.   Our summary of issues in the heart of the world's democracy, where one ethnic group is still systematically denied the right to vote.
5.   Proceedings Discontinued:    a 2006 return ten years later to Ukraine issues, one of my first human rights research missions in 1996
Torino, Italy, 2008
Special Remedy: Czech Schools
Italy: Campland
Romania: State of Impunity
France:   Get Out of Here!
Ukraine: Proceedings Discontinued
The Human Rights of People with Mental or Intellectual Impairments in the Republic of Moldova 
An Assessment of Key Aspects of the Domestic Law and Policy Framework in Light of the UN Convention on the Rights of Persons with Disabilities
We worked on this report over circa 5 years, jointly with a number of OHCHR colleagues, together with the Mental Disability Advocacy Centre MDAC).    In many ways, it is the record of our efforts to support a range of reforms in the Republic of Moldova.   Along the way, we learned an immense amount and, I believe, supported serious efforts to move forward reforms on the basis of the United Nations Convention on the Rights of Persons with Disabilities (CRPD), which Moldova ratified in 2010.     The report focusses on three rights in particular: (1) the rights to inclusive education; (2) the right to legal capacity; and (3) the right to independent living in the community.    It was published in July 2015, almost five years to the day after Moldova ratified the CRPD treaty. 
Moldova CRPD Report July 2015