Perhaps you should try some spelling variations:
trinh vatn » trinh van, trinh han, trinh san
thong cong » trong cong, tong cong, thong thong
trinh vat » trinh van, trinh luat, sinh vat
chinh cau » chinh chau, chinh ca, chinh can
hoc dieu » hoc thieu, hoc hien
dieu can » dieu hanh, tiep can, dieu cua
cong tai » cong thai, cong tac, dong tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc dieu can - hanh ((trinh vat) or (trinh vatn)) thong cong tai chinh cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc dieu can - hanh ((trinh vat) OR (trinh vatn)) thong cong tai chinh cau.
• Adding a wildcard symbol may retrieve word variants: hoc dieu can - hanh ((trinh vat) or (trinh vatn)) thong cong tai chinh cau*.