Perhaps you should try some spelling variations:
hoach trinh » hanh trinh, hoach dinh, hoach trong
sach trinh » sach tranh, hanh trinh, sach kinh
than khai » than khoi, tuan khai, than thoai
hoc sach » hoc sinh, hoc cac, hoc anh
trinh do » trinh ky
han khi » ban khi, van khi, than khoi
do khi » doi khi, do thi, co khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( hoc sach trinh do khi đong luc ) or ( thu hoach trinh ((han khi) OR (than khai)) đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc sach trinh do khi đong luc ) OR ( thu hoach trinh ((han khi) OR (than khai)) đong luc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( hoc sach trinh do khi đong luc ) or ( thu hoach trinh ((han khi) OR (than khai)) đong luc ))*".