Perhaps you should try some spelling variations:
thuoc va » thuoc ma, thuong va, thuoc tai
cua tren » dua tren, ca tren, cua tre
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
danh ve » dinh ve, hanh ve, anh ve
va nam » van nam, ha nam, va nay
ve cua » le cua, de cua, te cua
x hoi » o hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((x hoi) or (xa hoi)). lieu va nam ((thuoc va) OR (thuc va)) danh ve cua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). lieu va nam ((thuoc va) OR (thuc va)) danh ve cua tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (xa hoi)). lieu va nam ((thuoc va) OR (thuc va)) danh ve cua tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). lieu va nam ((thuoc va) OR (thuc va)) danh ve cua tren*.