Perhaps you should try some spelling variations:
dang khai » dang khoi, dang hai, quang khai
dang thai » dang thi, dang hai, lang thai
ban nuoc » ban duoc, ban nuoi, ban thuoc
sach ky » sac ky, sach y, sach kem
thi van » thi lan, thi hanh, thi nang
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc ((sach ky) or (sach ty)) nang x hoi. thi van ban nuoc va ((dang thai) OR (dang khai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc ((sach ky) OR (sach ty)) nang x hoi. thi van ban nuoc va ((dang thai) OR (dang khai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach ky) or (sach ty)) nang x hoi. thi van ban nuoc va ((dang thai) OR (dang khai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ky) or (sach ty)) nang x hoi. thi van ban nuoc va ((dang thai) OR (dang khai)) cua tre*.