Perhaps you should try some spelling variations:
tham thuc » nham thuc, tam thuc, thai thuc
pham thuc » phap thuc, pham chuc, nham thuc
su sach » so sach, vu sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
ve cua » le cua, de cua, te cua
su sac » su cac, su xac
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) or (su sach)) ky tang ma hoi. lieu va ((tham thuc) or (pham thuc)) va hanh ve cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky tang ma hoi. lieu va ((tham thuc) OR (pham thuc)) va hanh ve cua te.
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su sach)) ky tang ma hoi. lieu va ((tham thuc) or (pham thuc)) va hanh ve cua te*.