Perhaps you should try some spelling variations:
tham thuc » pham thuc, tam thuc, thai thuc
nham thuc » nhan thuc, nam thuc, nham thu
tu sach » thu sach, su sach, te sach
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
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: ((tu sach) or (thuat song)) ky dang xa hoi. hieu va ((tham thuc) or (nham thuc)) va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat song)) ky dang xa hoi. hieu va ((tham thuc) OR (nham thuc)) va hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat song)) ky dang xa hoi. hieu va ((tham thuc) or (nham thuc)) va hanh vi cua te*.