Perhaps you should try some spelling variations:
thuat sac » thuat sach, thuat san, thuat tac
dang thai » dang thi, dang hai, dang khai
thai cua » than cua, tai cuc, tri cua
van dang » van dong, van dung, van nang
nuoc van » nuoc va, nuoc san, luoc van
cau nuoc » cap nuoc, cac nuoc, dau nuoc
hieu van » hieu va, thien van, lieu va
van cau » van dau, van hau, van chat
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
sac ky » cac ky, sai ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sac ky ((((nang xa) OR (nang ma))) or (sang ma)) hoi. hieu van cau nuoc van dang thai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sac ky ((((nang xa) OR (nang ma))) OR (sang ma)) hoi. hieu van cau nuoc van dang thai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sac ky ((((nang xa) OR (nang ma))) or (sang ma)) hoi. hieu van cau nuoc van dang thai cua te".
• Adding a wildcard symbol may retrieve word variants: thuat sac ky ((((nang xa) OR (nang ma))) or (sang ma)) hoi. hieu van cau nuoc van dang thai cua te*.