Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
phap thuc » phap thu, phap hoc, phap tu
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
sach ky » sac ky, sach y, sach ty
te cua » tue cua, le cua, de cua
ve cua » le cua, de cua, ve cum
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky tang ma hoi. lieu va ((tham thuc) or (phap thuc)) va thanh ((ve cua) OR (te cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang ma hoi. lieu va ((tham thuc) OR (phap thuc)) va thanh ((ve cua) OR (te cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang ma hoi. lieu va ((tham thuc) or (phap thuc)) va thanh ((ve cua) OR (te cua)) te".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ma hoi. lieu va ((tham thuc) or (phap thuc)) va thanh ((ve cua) OR (te cua)) te*.