Perhaps you should try some spelling variations:
hoach dat » hoach xay, hoach va, sach dat
thanh tai » thanh hai, thanh toan, doanh tai
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
sach ky » sac ky, sach ty, sach kem
nang ma » tang ma, sang ma, nang cao
hoc dat » hoc dan, hoc dai, hoc phat
tai cua » thai cua, tai cuc, tri cua

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 ky) or (sach y)) nang ma hoa. hieu van ((hoach dat) or (hoc dat)) va thanh tai cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang ma hoa. hieu van ((hoach dat) OR (hoc dat)) va thanh tai cua vat.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang ma hoa. hieu van ((hoach dat) or (hoc dat)) va thanh tai cua vat*.