Perhaps you should try some spelling variations:
lam thuoc » nam thuoc, am thuc, cay thuoc
doc sach » hoc sach, toc sach, nuoc sach
viet cua » viec cua, viet qua, biet cua
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
lam duoc » nam duoc, luat duoc, tao duoc
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
sach ky » sac ky, sach y, sach ty
viet ca » viet ha, viet co, viet a
va danh » va dinh, va dan, va hanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky dang xay hoi. hieu van ((lam duoc) or (lam thuoc)) va danh ((viet cua) OR (viet ca)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky dang xay hoi. hieu van ((lam duoc) OR (lam thuoc)) va danh ((viet cua) OR (viet ca)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky dang xay hoi. hieu van ((lam duoc) or (lam thuoc)) va danh ((viet cua) OR (viet ca)) te".
• Adding a wildcard symbol may retrieve word variants: doc sach ky dang xay hoi. hieu van ((lam duoc) or (lam thuoc)) va danh ((viet cua) OR (viet ca)) te*.