Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sang tai » hang tai, sang tao, tang tai
thanh ve » hanh ve, thanh va, thanh vien
thanh vi » hanh vi, thanh va, nhanh vi
cac tac » cac toc, cac bac, cac dac
cac tuc » cac toc, cac tu, cac nuoc
tai hai » thi hai, dai hai, tai ha
cuu tre » cua tre, cau tren, cau treo
y sang » _ sang, duy sang

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y sang tai hai. hieu qua ((cac tuc) OR (cac tac)) va ((thanh vi) or (thanh ve)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y sang tai hai. hieu qua ((cac tuc) OR (cac tac)) va ((thanh vi) OR (thanh ve)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y sang tai hai. hieu qua ((cac tuc) OR (cac tac)) va ((thanh vi) or (thanh ve)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach y sang tai hai. hieu qua ((cac tuc) OR (cac tac)) va ((thanh vi) or (thanh ve)) cuu tre*.