Perhaps you should try some spelling variations:
day tieng » va tieng, ban tieng, dau tien
nam thuoc » nam thuc, nam thu, nha thuoc
dau tieng » dau tien, cau tieng, mau tieng
thu sach » thuat sach, thuoc sach, thu hoach
thuoc va » thuc va, thuoc ma, thuong va
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
va nam » van nam, ha nam, va nay
x hoi » xa hoi, o hoi, x ho

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)) ty nang x hoi. hieu va nam thuoc va danh vi ((dau tieng) OR (day tieng))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty nang x hoi. hieu va nam thuoc va danh vi ((dau tieng) OR (day tieng)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ty nang x hoi. hieu va nam thuoc va danh vi ((dau tieng) OR (day tieng))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ty nang x hoi. hieu va nam thuoc va danh vi ((dau tieng) OR (day tieng))*.