Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh tai » thanh toan, doanh tai, thanh san
chat duc » chat xuc, chat doc, chet duoc
nang dau » hang dau, xang dau, nang du
duc van » duc va, duc tan, duc manh
ve chat » va chat, van chat
sach ky » sac ky, sach y, sach kem
hieu ve » hieu va, hieu van
dau hoi » cau hoi, dai hoi, dan hoi
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet

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) or (sach ty)) nang dau hoi. hieu ve chat duc van ((thanh tai) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang dau hoi. hieu ve chat duc van ((thanh tai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) nang dau hoi. hieu ve chat duc van ((thanh tai) OR (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang dau hoi. hieu ve chat duc van ((thanh tai) OR (thanh hai)) cua tre*.