I found the information about the Turkistan Desert in a children's book called Discover Deserts, by Jennifer Vogelgesang (HTS Books, 1992). It says that their are five major deserts in Asia - they are:
Thar (in India)
Gobi (in China and Mongolia)
Turkistan (in central Asia)
However, it seems that deserts (like so many other things in the realm of "world knowledge") are classified in many different ways. When I was researching for AWOA, I found that there were SO MANY inconsistencies in information! One book would say that there were X number of deserts and another would list a different number. I found the same thing with oceans and with so many other topics. It seems that there is nothing certain "under the sun!" Different scholars disagree on the classification systems, I guess. It is in an historical and geographical region known as Turkistan (named for the many Turkic nationalities that live in this area). This is the area including Middle Asia and Kazakhstan. To find it - find the area directly south of the Tien Shan Mountain Range (look about 600 miles north of the Himalayan Range). Deserts - like mountain ranges - often cross borders and are not "considerate" enough to help geography students by staying within one country!!!
I hope none of you were too frustrated in not being able to find it - but just think about how much you and your children learned about other geographical landmarks while searching (endlessly) for it! I was concerned about the name "Turkistan" because of the fact that some of the countries (especially in this area of the world) change names of their cities, geographical landmarks, and even country names on practically a daily basis - especially since the changeover from the former Soviet Union.