Perhaps you should try some spelling variations:
thanh dat » thanh san, thanh hai, thanh van
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
mai khoi » mai khoa, tai khoa, cac khoi
va cham » va chat, va tham
dat cua » dai cua, day cua, mat cua
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cac, va cao, va cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang ((ma hoi) or (mai khoi)). hieu ((va cam) OR (va cham)) truc va thanh dat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((ma hoi) OR (mai khoi)). hieu ((va cam) OR (va cham)) truc va thanh dat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((ma hoi) or (mai khoi)). hieu ((va cam) OR (va cham)) truc va thanh dat cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((ma hoi) or (mai khoi)). hieu ((va cam) OR (va cham)) truc va thanh dat cua tre*.