The vast majority of the Donauschwaben settlers in Hrastovac and surrounding area came after 1865 from the counties of Tolna, Baranya and Somogy, known as Swabian Turkey. Here is some information on that area: 

Researching-in-Swabian-Turkey by Wally Schlegel

Swabian-Turkey-German-localities

Swabian-Turkey Book Resources: http://www.swabiantrek.com/

  TOLNA, "Herkunft deutscher Ansiedler im Komitat Tolnau" by Josef Schmidt and Johann Müller, Sindelfingen 1995

BARANYA: "Deutsche Kolonisten im Komitat Baranya/Ungarn 1688-1752" by Ferdinand Hengl 

Book: CHILDREN OF THE DANUBE, By Henry Fischer, http://www.swabiantrek.com/

    IZMÉNY, Tolna, "Izmény, eine ehemalige deutsche Gemeinde in der Tolnau" by Georg Müller, ISBN: 9632026314

KISMÁNYOK, Tolna Heimatbuch can be ordered from

Heinrich Frey, Guttenbrunnstr. 92, D 71067 Sindelfingen, Germany

MAJÓS, Tolna: "Heimatbuch und Ortschronik von Majos / Majesch" by Heinrich März 

VARSAD, Tolna: "Varsad, Ein Dorf, Eine Heimat, Unsere Heimat" by Heinrich Weissenberger 

Some of our Hrastovac ancestors came originally from Hessen down the River Danube to the Swabian Turkey areas. See:

Hessian Emigration: Hessian-Emigrants-to-Hungary