Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
qua cau » quan cau, qua cac, qua ca
truc va » thuc vat, trung va
thuc va » thuc vat, thuc dan, thuc day
hanh va » hang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky lang xa hoi. hieu qua cau ((truc va) or (thuc va)) ((hanh va) OR (hanh vi)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky lang xa hoi. hieu qua cau ((truc va) OR (thuc va)) ((hanh va) OR (hanh vi)) cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky lang xa hoi. hieu qua cau ((truc va) or (thuc va)) ((hanh va) OR (hanh vi)) cau tren".
• Adding a wildcard symbol may retrieve word variants: vu sach ky lang xa hoi. hieu qua cau ((truc va) or (thuc va)) ((hanh va) OR (hanh vi)) cau tren*.