Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
tham thuc » nham thuc, pham thuc, tam thuc
tham luc » than luc, tham nuoc, nhan luc
trinh vi » trinh va, trinh ve, trinh viet
cau tren » cu tren, dau tren, ca tren
tinh vi » tinh voi, tinh va, dinh vi
sach v » sach va, sach y, sach 2
nang o » nang co, nang ho, nang ro
v nang » va nang, vu nang, van nang
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach v nang o hoi. lieu va ((tham luc) OR (tham thuc)) va ((tinh vi) or (trinh vi)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach v nang o hoi. lieu va ((tham luc) OR (tham thuc)) va ((tinh vi) OR (trinh vi)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach v nang o hoi. lieu va ((tham luc) OR (tham thuc)) va ((tinh vi) or (trinh vi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: thuoc sach v nang o hoi. lieu va ((tham luc) OR (tham thuc)) va ((tinh vi) or (trinh vi)) cau tren*.