NLTE analysis of spectra: OBA stars
  Methods of calculation of NLTE model atmosphere are discussed. The NLTE trace element procedure is compared with the full NLTE model atmosphere calculation. Differences between LTE and NLTE atmosphere modeling are evaluated. The ways of model atom construction are discussed. Finally, modelling of expanding atmospheres of hot stars with winds is briefly reviewed. 
Ji\v{r}\'i Kub\'at and Brankica \v{S}urlan
astro-ph.SR