Perhaps you should try some spelling variations:
"plant proceeding series ;" » "plant processing series ;", "plant bioprocessing series ;", "plant proceedings series ;", "planet proceedings series ;", "plans proceedings series ;"
"plant breeding systems ;" » "plant feeding systems ;", "plant building systems ;", "plant trading systems ;"
"plant breeding sites ;" » "plant breeding united ;", "plant breeding system ;", "plant breeding series ;"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("plant proceeding series ;") OR ("plants proceedings series ;"))) or ((("plant breeding sites ;") or ("plant breeding systems ;"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("plant proceeding series ;") OR ("plants proceedings series ;"))) OR ((("plant breeding sites ;") OR ("plant breeding systems ;")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"plant proceeding series ;\") OR (\"plants proceedings series ;\"))) or (((\"plant breeding sites ;\") or (\"plant breeding systems ;\"))))".
• Removing quotes may allow a broader search: (((( plant proceeding series ; ) OR ( plants proceedings series ; ))) or ((( plant breeding sites ; ) or ( plant breeding systems ; )))).
• Adding a wildcard symbol may retrieve word variants: (((("plant proceeding series ;") OR ("plants proceedings series ;"))) or ((("plant breeding sites ;") or ("plant breeding systems ;"))))*.