Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong tan, truong thanh
trinh chao » trinh chat, trinh han, trinh giao
cong hanh » cong khanh, hong hanh, song hanh
chao van » cao van, hao van, thao van
hoc viet » hoc hien
trinh co » trinh do, trinh cong, trinh hoa
hoi viet » hai viet, thai viet, cuoi viet
tao cay » tao cao, tao may, tao cac
cao cay » cao cap, cho cay, ca cay
oi viet » o viet, cuoi viet, gioi viet
cac cay » ca cay, cac cam, cac cap
can ban » van ban, toan ban
va can » va chan, va cao, va con
co hoi » co loi
lan va » luan va, lanh va, lan van
co lan » cao lan, co ban, co dan
cay co » cac co, tay co, cay cong
van va » van vat, van van, ban va
ban co » ban do, san co
co oi » co loi, co doi, co toi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( cong trinh ((cong hanh) or (cong thanh)) va cac cay co hoc viet nam ) or ( cong trinh co lan va can ban co hoi viet nam ))) or ( cong trinh chao van va ((cao cay) OR (tao cay)) co oi viet nam ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh ((cong hanh) OR (cong thanh)) va cac cay co hoc viet nam ) OR ( cong trinh co lan va can ban co hoi viet nam ))) OR ( cong trinh chao van va ((cao cay) OR (tao cay)) co oi viet nam )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh ((cong hanh) or (cong thanh)) va cac cay co hoc viet nam ) or ( cong trinh co lan va can ban co hoi viet nam ))) or ( cong trinh chao van va ((cao cay) OR (tao cay)) co oi viet nam ))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh ((cong hanh) or (cong thanh)) va cac cay co hoc viet nam ) or ( cong trinh co lan va can ban co hoi viet nam ))) or ( cong trinh chao van va ((cao cay) OR (tao cay)) co oi viet nam ))*.