Perhaps you should try some spelling variations:
sach giac » sach giao, canh giac, cach giao
giac duoc » giao duc, gia duc
duoc khoa » nuoc khoa, duc khoa, huoc khoa
pham xuan » pham luan, pham quang, pham van
khoa hoc » hoa hoc
sam quan » nam quan, san quan, tam quan
sau quan » su quan, san quan, dau quang
te sach » toc sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach giac duoc khoa hoc - stem. ((pham xuan) or (((sam quan) OR (sau quan)))) nam~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach giac duoc khoa hoc - stem. ((pham xuan) OR (((sam quan) OR (sau quan)))) nam.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach giac duoc khoa hoc - stem. ((pham xuan) or (((sam quan) OR (sau quan)))) nam".
• Adding a wildcard symbol may retrieve word variants: te sach giac duoc khoa hoc - stem. ((pham xuan) or (((sam quan) OR (sau quan)))) nam*.