Perhaps you should try some spelling variations:
gray » ray, graw
grand » grant, brand
grail » rail, trail, frail
rain » gain, rail
grain » ggain, grail
brain » bgain, brail
irand » brand, iran, rand
rank » ranks, frank
sand » san, hand
band » bond
irans » iran, trans, frans

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((((((hard or ((gray or (grand or (grail or (rain or main)))) or irand)) or had) or rank) or (sand or stand)) or land) or (band or bank)) or (irans or (grain OR brain))) counterinsurgency study ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((((((hard OR ((gray OR (grand OR (grail OR (rain OR main)))) OR irand)) OR had) OR rank) OR (sand OR stand)) OR land) OR (band OR bank)) OR (irans OR (grain OR brain))) counterinsurgency study ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((((((hard or ((gray or (grand or (grail or (rain or main)))) or irand)) or had) or rank) or (sand or stand)) or land) or (band or bank)) or (irans or (grain OR brain))) counterinsurgency study ;".
• Adding a wildcard symbol may retrieve word variants: (((((((hard or ((gray or (grand or (grail or (rain or main)))) or irand)) or had) or rank) or (sand or stand)) or land) or (band or bank)) or (irans or (grain OR brain))) counterinsurgency study ;*.