Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
hoc thuc » hoc huu
hac thuc » ha thuc, thach thuc, thuc thuc
sach ky » sach y, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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

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