Perhaps you should try some spelling variations:
hoach trinh » hanh trinh, hoach dinh, hoach trong
sach trinh » sach tranh, hanh trinh, sach kinh
trinh han » trinh quan
hoc sach » hoc sinh, hoc cac, hoc anh
trinh o » trinh do, trinh co, trinh mo
han khi » ban khi, van khi, than khai
o khi » co khi, bo 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 o khi đong luc ) or ( thu hoach trinh han khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc sach trinh o khi đong luc ) OR ( thu hoach trinh han khi đong luc ))*.