Perhaps you should try some spelling variations:
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
cac hoc » cach hoc, cac hop, bac hoc
dan via » dan va, dan gian, dan giai
dan gia » dan gian, danh gia, dan giai
y nang » ky nang, ly nang, v nang

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 (su sach)) y nang xa hoi. hieu qua cac hoc va ((dan via) or (dan gia)) cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) y nang xa hoi. hieu qua cac hoc va ((dan via) OR (dan gia)) cua vat.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) y nang xa hoi. hieu qua cac hoc va ((dan via) or (dan gia)) cua vat*.