Perhaps you should try some spelling variations:
thanh da » thanh dat, thanh dam, thanh dan
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, ca tren
sach ky » sach y, sach ty, sach kem
nang ma » tang ma, sang ma, mang may
van lam » van nam
lam duc » lam duoc, pham duc, nam duoc
sac ky » cac ky, sai ky
da cau » dat cau, va cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sac ky)) ((nang ma) OR (nang cao)) hoi. hieu van lam duc va thanh da cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) ((nang ma) OR (nang cao)) hoi. hieu van lam duc va thanh da cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sac ky)) ((nang ma) OR (nang cao)) hoi. hieu van lam duc va thanh da cau tren".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) ((nang ma) OR (nang cao)) hoi. hieu van lam duc va thanh da cau tren*.