Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
hoc dat » hoc dan, hoc dai, hoc phat
hac dat » tac dat, hoach dat, nhac dan
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua
de cua » le cua, te cua, dieu cua

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 sang ma hoi. hieu van ((hac dat) or (hoc dat)) va thanh ((vi cua) or (de cua)) vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky sang ma hoi. hieu van ((hac dat) OR (hoc dat)) va thanh ((vi cua) OR (de cua)) vat.
• Adding a wildcard symbol may retrieve word variants: thu sach ky sang ma hoi. hieu van ((hac dat) or (hoc dat)) va thanh ((vi cua) or (de cua)) vat*.