Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sang mai » sang ma, sang tai, lang mai
mai hoi » mai khoi, dai hoi, lai hoi
la tren » loai tren, dua tren, dat tren
y sang » _ sang, duy sang
ve cac » va cac, vien cac
xuc va » tuc va, luc va, xac va
van la » van lam, van lao, van lan

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 mai hoi. hieu ((va bai) or (ve cac)) ((xuc va) OR (duc va)) dinh van la tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y sang mai hoi. hieu ((va bai) OR (ve cac)) ((xuc va) OR (duc va)) dinh van la tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y sang mai hoi. hieu ((va bai) or (ve cac)) ((xuc va) OR (duc va)) dinh van la tren".
• Adding a wildcard symbol may retrieve word variants: thuat sach y sang mai hoi. hieu ((va bai) or (ve cac)) ((xuc va) OR (duc va)) dinh van la tren*.