One option is a picture of one of the characters from the movie, such as Jake Sully or Trudy Chacon, both of whom are humans in the film.
Schrenck, Reisen and Forschungen im Amurgebiet (St Petersburg, 1858-1891); Trudy of the Siberian expedition - mathematical part (also geographical) by Schwarz, and physical part by Schmidt, Glehn and Brylkin (1874, seq.); G.
Kozlov, Trudy Ekspeditsiy Imp. Russ.
Roborovsky, Trudy Tibetskoi Ekspeditsiy, 1889-1890; K.
Vostochnom Turkestane and Trudy Tibetskoy Ekspeditsiy, 1889-1890 (St Petersburg, 1891-1892); V.