Perhaps you should try some spelling variations:
van tuan » van quan, van ban, anh tuan
cham duc » pham duc, cham soc, pham duy
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
tuan va » toan va, luan va, quan va
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
ha hoi » hoa hoi, ha noi, xa hoi
va cua » va chua, via cua, ca cua

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 ((ky lang) OR (ky tang)) ha hoi. ((hieu ve) OR (hieu va)) cham duc van tuan va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) OR (ky tang)) ha hoi. ((hieu ve) OR (hieu va)) cham duc van tuan va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) OR (ky tang)) ha hoi. ((hieu ve) OR (hieu va)) cham duc van tuan va cua tre*.