Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
thien va » thien van, tien va, thien tai
phat day » phap day, phan day, phan dau
va trien » va truyen, va thiet, va tuyen
tu sach » su sach, te sach, tu cach
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
tinh do » trinh do, tinh doi, tinh da
do va » do van, so va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((tu sach) or (thu sach))) or (vu bach)) tu nang xa hoi. thien va phat day va tinh do va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thu sach))) OR (vu bach)) tu nang xa hoi. thien va phat day va tinh do va trien.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (thu sach))) or (vu bach)) tu nang xa hoi. thien va phat day va tinh do va trien*.