Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thu sach » tu sach, thuat sach, thuoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cao hoi » cau hoi, co hoi, cao hoc
hieu vu » hieu va, hieu ve, hieu su
vu tham » va tham, vu kham, vu cham
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
va vuai » va vai

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 ty nang cao hoi. hieu vu tham thuc va hanh ((va vua) or (va vuai)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang cao hoi. hieu vu tham thuc va hanh ((va vua) OR (va vuai)) thiet.
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang cao hoi. hieu vu tham thuc va hanh ((va vua) or (va vuai)) thiet*.