Perhaps you should try some spelling variations:
thuat sac » thuat sach, thuat san, thuat tac
dang thai » dang thi, dang hai, dang khai
cau nuoc » cap nuoc, cac nuoc, dau nuoc
nuoc van » nuoc va, nuoc san, luoc van
van dang » van dong, van dung, van nang
thai cua » than cua, tai cuc, tri cua
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
sac ky » cac ky, sai ky
va cau » van cau, va cac, va dau
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)) hoi. hieu va 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)) hoi. hieu va cau nuoc van dang thai cua te.
• Adding a wildcard symbol may retrieve word variants: thuat sac ky ((nang xa) or (nang ma)) hoi. hieu va cau nuoc van dang thai cua te*.