Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
sach tren » sach tien, sach tranh
toc sach » hoc sach, doc sach, thuoc sach
tu hanh » du hanh, lu hanh, thuc hanh
trinh y » trinh ky, trinh ly, trinh _
my khi » ky khi, my chi
ly khi » ly chi
y khi » ky khi, y chi, y nhi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu hanh trinh y khi đong luc ) or ( toc sach tren ((my khi) OR (ly khi)) đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hanh trinh y khi đong luc ) OR ( toc sach tren ((my khi) OR (ly khi)) đong luc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu hanh trinh y khi đong luc ) or ( toc sach tren ((my khi) OR (ly khi)) đong luc ))*".