Perhaps you should try some spelling variations:
su triet » su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
vat hanh » vat thanh, van hanh, va hanh
dang hoa » dang hoai, dang khoa, dong hoa
tu sach » thu sach, te sach, tu cach
thu vat » thuc vat, thu va, thuat vat
hieu he » hieu ve, hiem he, hieu le
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky dang » ky nang, ky danh
su sach » so sach, vu sach
su viet » so viet
he nam » ha nam, nghe nam

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 (su sach)) ky dang hoa hoi. hieu he nam thu vat hanh vai ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky dang hoa hoi. hieu he nam thu vat hanh vai ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky dang hoa hoi. hieu he nam thu vat hanh vai ((su triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky dang hoa hoi. hieu he nam thu vat hanh vai ((su triet) or (su viet))*.