Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
su sach » so sach, vu sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
qua hai » qua hoat
truc va » thuc va, thuc vat, trung va
tuc va » thuc va, tuc xa, duc va
cua tu » cua tuc, cua su, cua cu

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 ((ky lang) or (ky tang)) xa hoi. hieu qua hai ((tuc va) OR (truc va)) vanh dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky lang) OR (ky tang)) xa hoi. hieu qua hai ((tuc va) OR (truc va)) vanh dai cua tu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky lang) or (ky tang)) xa hoi. hieu qua hai ((tuc va) OR (truc va)) vanh dai cua tu*".