This new volume edited by Trevor Marchand will be of interest to a wide variety of people. It should be noted that some of the proceeds will go to UNHCR’s assistance to the humanitarian crisis in Yemen. It can be ordered from the University of Chicago Press.
Pinterest has a number of photographs from the late Ottoman era in Ṣan‘ā’. Here are a few:
The Bekreyia Ottoman mosque ca. 1895
Ṣan‘ā’ scene around 1900
Ottoman military barracks around 1900
Ottoman soldiers in Manākha around 1911
Ottomans and Yemenis around 1900