Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
trinh vat » trinh van, sinh vat, trinh han
theo chu » theo chieu, cho chu, chao chu
ho chieu » theo chieu, hoc thieu, doi chieu
cong ban » cong bang, cong san, cong tan
ban thi » dan thi, van thi, can thi
thi cao » thai cao, thi hao, thi bao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chu) OR (ho chieu)) sach - hanh ((trinh vat) OR (trinh luat)) thong cong ban thi cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chu) or (ho chieu)) sach - hanh ((trinh vat) OR (trinh luat)) thong cong ban thi cao~".
• Adding a wildcard symbol may retrieve word variants: ((theo chu) or (ho chieu)) sach - hanh ((trinh vat) OR (trinh luat)) thong cong ban thi cao*.