Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hanh tai » thanh tai, hang tai, han tai
tu cach » tu cac
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
duoc va » nuoc va, duc va, duoc ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
long ha » dong ha, cong ha, dong hoa
va tao » va bao, va cao, va tac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thuat sach)) ky ((lang ha) OR (long ha)) hoi. hieu va tao duoc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thuat sach)) ky ((lang ha) OR (long ha)) hoi. hieu va tao duoc va hanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thuat sach)) ky ((lang ha) OR (long ha)) hoi. hieu va tao duoc va hanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thuat sach)) ky ((lang ha) OR (long ha)) hoi. hieu va tao duoc va hanh tai cua tre*.