Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh van » thanh san, thanh toan, thanh phan
thanh dat » thanh san, thanh hai, thanh ha
suu viet » su viet, sau viet, sieu viet
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
dang ma » dang mau, dang mam, dang mat
ky dang » ky nang, ky danh
co toc » cao toc, co doc, co toi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky dang ma hoa. hieu va ((co toc) or (co hoc)) xa ((thanh dat) OR (thanh van)) suu viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky dang ma hoa. hieu va ((co toc) OR (co hoc)) xa ((thanh dat) OR (thanh van)) suu viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky dang ma hoa. hieu va ((co toc) or (co hoc)) xa ((thanh dat) OR (thanh van)) suu viet".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky dang ma hoa. hieu va ((co toc) or (co hoc)) xa ((thanh dat) OR (thanh van)) suu viet*.