Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
khien cua » khien qua, khien tu, dien cua
trien cua » truyen cua, trien nha, tri cua
doc sach » hoc sach, toc sach, nuoc sach
qua tham » qua cham, qua than, qua thanh
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
khi cua » chi cua, thai cua
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. hieu qua tham thuc va danh ((((khien cua) or (khi cua))) or (trien cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky nang x hoi. hieu qua tham thuc va danh ((((khien cua) OR (khi cua))) OR (trien cua)) te.
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang x hoi. hieu qua tham thuc va danh ((((khien cua) or (khi cua))) or (trien cua)) te*.