Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
thuoc va » thuc va, thuoc ma, thuong va
cua tren » dua tren, ca tren, cua tre
tu sach » su sach, te sach, tu cach
va danh » va dinh, va dan, va hanh
danh ve » dinh ve, hanh ve, anh ve
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) OR (thu sach)) ky nang ((x hoi) or (xa hoi)). hieu van nam thuoc va danh ve cua tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang ((x hoi) OR (xa hoi)). hieu van nam thuoc va danh ve cua tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang ((x hoi) or (xa hoi)). hieu van nam thuoc va danh ve cua tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang ((x hoi) or (xa hoi)). hieu van nam thuoc va danh ve cua tren*.