Perhaps you should try some spelling variations:
sach trinh » sach tranh, hanh trinh, sach kinh
trinh cong » trinh dung
cong thanh » dong thanh, cong trinh, cong tan
sach nganh » sach ngan, sach tranh, cac nganh
nganh my » nganh y, nganh ma, nganh ky
su sach » so sach, vu sach
my khi » ly khi, ky khi, my chi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su sach trinh cong thanh đong luc ) or ( su sach nganh my khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su sach trinh cong thanh đong luc ) OR ( su sach nganh my khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( su sach trinh cong thanh đong luc ) or ( su sach nganh my khi đong luc ))*.