Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hang dai » hoang dai, hang tai, hang dau
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
truc va » thuc vat, trung va
thuc va » thuc vat, thuc dan, thuc day
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: su sach y nang mai hoi. hieu ve cham ((truc va) or (thuc va)) hang dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang mai hoi. hieu ve cham ((truc va) OR (thuc va)) hang dai cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang mai hoi. hieu ve cham ((truc va) or (thuc va)) hang dai cua viet*.