For some of the 'undated' book covers it is possible to at least assert the year of print because they seem to be limited prints certified with a handwritten note in French.
Fore example on the Khôn Sống Dại Chết book cover it is handwritten "tirage 1000 Saigon le 27/1/34". So it is a 1,000 copy print certified as such on the 27th January 1934.
Fore example on the Khôn Sống Dại Chết book cover it is handwritten "tirage 1000 Saigon le 27/1/34". So it is a 1,000 copy print certified as such on the 27th January 1934.