Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
toc sach » hoc sach, doc sach, thuoc sach
vat hanh » vat thanh, van hanh, va hanh
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu vu » hieu va, hieu ve, hieu su
vu pham » su pham, vi pham, vu kham
vai cua » hai cua, lai cua, bai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky lang xa hoi. hieu vu pham thuc vat hanh ((vai cua) OR (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. hieu vu pham thuc vat hanh ((vai cua) OR (dai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky lang xa hoi. hieu vu pham thuc vat hanh ((vai cua) OR (dai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky lang xa hoi. hieu vu pham thuc vat hanh ((vai cua) OR (dai cua)) triet*.