Eleven volumes: The introductory volume, 'The 20 Best Novels of Thailand' by Marcel Barang, containing the background and general history of the novel in Thailand, biographical pieces re the selected authors and extracts from the novels; together with the first ten volumes of the series:
'The Path of the Tiger' by Sila Khoamchai (first published 1989)
'The Circus of Life' by Arkartdamkeung Rapheephat (1929)
'The Story of Jan Darra' by Utsana Phleungtham (1966)
'The Judgment' by Chart Korpjitti (1981)
'An Elephant Named Maliwan' by Thanorm Maha Paoraya (1946)
'Of Time and Tide' by Atsiri Thammachoat (1985)
'The Field of the Great' by Marlai Choophinit (1954)
'Snakes' by Wimon Sainimnuan (1984)
'Wanlaya's Love' by Seinee Saowaphong (1952)
'Time in a Bottle' by Praphatsorn Seiwikun (1985)
Volumes 1-5 and 8 translated into English by Phongdeit Jiangphatthanarkit, volumes 6-7 and 9 by Marcel Barang, volume 10 by Barang and Jiangphatthanarkit, introductions and notes to all ten volumes by Marcel Barang. As far as I can see, the series reached ten of the proposed twenty volumes.