Perhaps you should try some spelling variations:
gat thanh » dat thanh, tat thanh, vat thanh
thanh ve » hanh ve, thanh va, thanh vien
truc gat » truc giac, truc va, truc may
toc sach » hoc sach, doc sach, thuoc sach
tu sach » thu sach, su sach, tu cach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
tang ha » lang ha, tang ma, trung ha
ky tang » ky nang, ky dang, kho tang
va cau » van cau, va cac, va dau
ve cua » le cua, de cua, te cua
ha hoi » hoa hoi, ha noi, xa hoi

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) or (((te sach) OR (toc sach)))) ky tang ha hoi. hieu va cau truc gat thanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((te sach) OR (toc sach)))) ky tang ha hoi. hieu va cau truc gat thanh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (((te sach) OR (toc sach)))) ky tang ha hoi. hieu va cau truc gat thanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((te sach) OR (toc sach)))) ky tang ha hoi. hieu va cau truc gat thanh ve cua tre*.