Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
trinh vi » trinh va, trinh ve, trinh viet
than duc » tran duc, phan duc, than doc
cau tren » cu tren, dau tren, ca tren
nang ro » nang co, nang ho, nang rong
nang ra » nang ma, lang ra, nang va
tinh vi » tinh voi, tinh va, dinh vi
va than » va thanh, van than, va phan
sach v » sach va, sach y, sach 2

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 ra) OR (nang ro)) hoi. lieu va than duc 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 ra) OR (nang ro)) hoi. lieu va than duc 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 ra) OR (nang ro)) hoi. lieu va than duc va ((tinh vi) or (trinh vi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: thuoc sach v ((nang ra) OR (nang ro)) hoi. lieu va than duc va ((tinh vi) or (trinh vi)) cau tren*.