APA
Humboldt A. V., .Letters of Alexander Von Humboldt: Written Between the Years 1827 and 1858, to Varnhagen Von Ense; Together With Extracts from Varnhagen's Diaries, and Letters from Varnhagen and Others. : Cambridge University Press.
Chicago
Humboldt Alexander Von, .Letters of Alexander Von Humboldt: Written Between the Years 1827 and 1858, to Varnhagen Von Ense; Together With Extracts from Varnhagen's Diaries, and Letters from Varnhagen and Others. : Cambridge University Press.
Harvard
Humboldt A. V., .Letters of Alexander Von Humboldt: Written Between the Years 1827 and 1858, to Varnhagen Von Ense; Together With Extracts from Varnhagen's Diaries, and Letters from Varnhagen and Others. : Cambridge University Press.
MLA
Humboldt Alexander Von, .: Cambridge University Press. .
