Sourced here is a cover of Dutch underground magazine Hitweek, depicting Frank Zappa. Of which Dr. Vinyl says:

Legendary Dutch underground music magazine. The first year was only available in Amsterdam ( 1965-1966) but the later issues also in other big Dutch cities. The was THE magazine for hippies, modsters and other long haired youngsters. Not like commercial magazines such as Muziek Expres or Muziek Parade HITWEEK was the magazine were you could find articles and pictures of obscure US, UK and Dutch bands such as THE OUTSIDERS, THE PINK FLOYD, Q65, THE CREATION, LAZY BONES, THE MOTHERS, VELVET UNDERGROUND + many many more. HITWEEK was also famous because of the artwork , especially the years 1967-1969 had GREAT psychedelic drawings and pictures. HITWEEK can be compared to the UK underground magazine IT!

The magazine’s editor was Willem De Ridder, who is connected to Jim Haynes, the Dutch Provos, the Fluxus art movement, Suck magazine and the whole late of sixties underground/counterculture Europe.

Do not confuse De Ridder with Bernard Willem Holtrop of Hara Kiri magazine.