Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
hieu su » hieu sau, tieu su, hieu so
hieu vu » hieu va, hieu ve, dieu vu
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
soc va » hoc va, loc va, doc va
va cua » va chua, via cua, ca cua

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 sang ma hoi. ((hieu vu) or (hieu su)) cham soc va danh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky sang ma hoi. ((hieu vu) OR (hieu su)) cham soc va danh va cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky sang ma hoi. ((hieu vu) or (hieu su)) cham soc va danh va cua tre*.