Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cay viet » ca viet, tay viet, cao viet
cua cay » cua cac
dau cua » dai cua, day cua, cau cua
su cham » su pham, tu cham, vu cham
hieu su » hieu sau, tieu su, hieu so
tu sach » thu sach, su sach, te sach
nang xa » lang xa, nang ma, mang xa
soc va » hoc va, loc va, doc va
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thuoc sach)) v ((nang xa) OR (nang x)) hoi. hieu su cham soc va dau cua cay viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) v ((nang xa) OR (nang x)) hoi. hieu su cham soc va dau cua cay viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) v ((nang xa) OR (nang x)) hoi. hieu su cham soc va dau cua cay viet*".